help me build a system for $1200

Keep Cambridge and NAD, add Adcom 600 or Assemblage 1.0 DAC for $150, Spendor SE used at $700, do some nice stands and Signal Cable PCs and wire. Done.

Whow, lots of interesting directions. A lot depends on what you are looking for. I think your idea of the Super-T amp is daring.. and would take you into adventurous territory. It is only about $130 at Parts Express, and you could experiment with full range hyper sensitive drivers, such as those offered by Audio Nirvana (http://www.commonsenseaudio.com/nirvana.html), for about $150 a pair- all you would have do to is find an enclosure for an 8 inch driver- or build your own based on the plans Audio Nirvana offers. You might end up with something special.
For a more conventional direction, I second the recommendations for a small creek integrated, which is going to be a big improvement over your NAD... but only if you upgrade the source too... like with a Lite DAC. Speakers... a lot of people are recommending Vandies... and that is for a reason.
Good luck

I am a medical student, and as such, already have tons of debt to begin with. That said, I've been wanting to upgrade my current system (cambridge audio CD player, squeezebox v3, a 10 year old NAD receiver, and a pair of minipod speakers that I received for free). I will probably keep the cambridge audio CD player for now.

You didn't give much in the way of specific data to go on; but I'll stick my neck out anyway...

First, for a ca. $1,200 budget, you'll likely be better off sticking to "Better Mid-Fi", than attempting to put together anything super exotic. Don't let the "Mid-Fi" moniker put you off -- as long as your doing this more for the music than the snob appeal, you can do quite well with brands like NAD, Adcom, Rotel, Hafler, etc. -- and occasionally, even the big "mass market" makers put out something halfway worthwhile (cf. some of the older Denon and Yamaha stuff).

Hence, as several other folks have suggested, you might want to also keep that NAD receiver, at least for awhile; but this depends greatly on just which one it is *AND* what kind of shape it's in. As a general rule, NAD's stuff is reasonably decent when it's new and working properly; but historically, the "low budget" build quality (how do you think they maintain that "bang for the buck" reputation, anyway?) leaves enough to be desired that after ten years, it may well be giving you some grief. If so, then I understand your desire to replace it. But if it's still working well, you would probably be better off putting at least *most* of the budget into speakers, and leaving the electronics upgrade for later. OTOH, if it's one of their real low-end "20-watt wonder" models, you will likely find yourself rather severely limited in your speaker choice. But then, on still another hand, as long as the NAD has a pair of line-level preamp-outs (which it probably does) this really is no big deal, as (again, assuming as the unit is otherwise working well) you can easily and cost-effectively add (now or later) a much beefier power amp without having to replace the tuner and preamp sections. For a few quick examples from the current Audiogon classifieds:

Adcom GFA555
Asking $350.00
http://cls.audiogon.com/cgi-bin/cls.pl?ampstran&1154420459

Adcom GFA-555
Asking $300.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?ampstran&1154197310

Mondial Acurus A200 Black pending
Asking $385.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?ampstran&1154190429

Parasound HCA-1000
Asking $275.00 SOLD
http://cls.audiogon.com/cgi-bin/cls.pl?ampstran&1154107140

So, based on the above, you should be able to devote at least $800-900 of your budget to speakers; and that seems about right to me, given what you've told us. But there's no way that I or anyone else can pick a speaker for you "by remote control". There's just too wide a gamut of widely disparate speakers -- all ostensibly "good"; and none of us have *your* ears. So the only thing to do is start listening. Beat the bricks and visit every decent audio store within driving distance, to get an idea of what you like. Go ahead and consider models somewhat above your budget, on the theory that you may be able to find an "affordable" used specimen; but beware that if you really get your heart set on something you can't afford to buy new, this might mean waiting quite awhile for _The_Right_ pair of used speakers to come along. Once you've narrowed it down to, say, 3-6 different makes/models, start perusing the classifieds here and elsewhere.

A few other comments...

Both of the speakers you mentioned are small "mini-monitor" types. Do you have a space problem that you didn't mention? If not... Even ignoring the obvious bass-extension issue, in this price range a conventional full-size / full-range speaker will surely provide better overall performance, especially if you're short on amplifier power. Here again are a few quick examples from the current Audiogon classifieds listings:

Tannoy Revolution R-3 tower speakers
Asking $850.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154978341

Klipsch la scala
Asking $850.00
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154807972

Quad 22l
Asking $1050.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154790000

Focal jm lab Cobalt 816S
Asking $999.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154635779

KEF 104/2 reference
Asking $800.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154566026

Acoustic research AR-9 original
Asking $600.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154561963

Vandersteen 2Ce Signature oak trim
Asking $875.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154527335

Paradigm Reference studio 80 v.1
Asking $650.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154344313

B&W DM604
Asking $875.00 obo
http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1154295460

I need to emphasize here, these are *ONLY* examples. Not only is the above list bizarrely varied in terms of the general types and characters represented, speakers are by far the most subjective part of any system, and there is simply no substitute for getting out there and *listening*.

The room dimensions you quoted are not bad, actually; but there's far more to a "good" room than the basic dimensions. This is not the time or place to go into a treatise on room acoustics; but *do* put the time & effort into setting things up correctly (including some "creative decorating", if necessary), or your investment may well be largely wasted.

I like your Jolida idea, with some nice speakers. Very musical piece, with clear speakers, and you should be happy.

A know a couple of medical students, one of whom introduced me to this miserable hobby it causes an insidious incurable condition, audiosyncratic upgraditis. Unless there is something drastically wrong with your current system. Then I seriously recommend that you simply learn to to love the one you are with.
I would say that if you want to take the plunge into tubes which is a different type of audio the Jolida 302 with the Totem arrows is magical, but sweet and not meant to rock you. Otherwise just upgrade your mid-fi solid state amp. As recommended already, the Adcom, or an improved NAD, possibly Rotel or Accurus Etc.
Call my buddy at Quest for Sound, Stephen Monte. He will set you up tubes or SS. He is an Audiogon guild member you can look him up on these pages. No financial affiliation.