Newbie - Which USED Amp & Preamp for under $2500

Darkmoebius, Thanks, I have a couple questions...there is a Bryston 3B-ST available locally for $750. Otherwise there is a 4B-ST on Audiogon for $1350. Is the 3B something to consider, or is the 4B definitely worth the extra $$$?

I've heard a lot about the Mccormack DNA-125. Should I be concerned about the age of this amp?

In brief, what are the downsides to class d amps?

Would you recommend the Odyssey Stratos Extremes dual?:
http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1260018001&/Odyssey-Stratos-Extremes-Dual-

Thanks, this is a HUGE help

The Cary IA write-ups seem very positive for jazz, blues, classical. Are there other recommendations for specific IA's in this price range? What is the benefit of IA's over separates? Thanks!

As Kurt_Tank mentioned, it was advice that I didn't want to hear, however I'm glad he mentioned it. I'm not in the habit of continually swapping gear and I'd rather have more options when shopping for speakers. It looks I need to start researching Speakers, on which you'll probably see another thread from me shortly asking for advice.
Thanks everyone for your replies. I've been researching each and every suggestion posted.

Darkmoebius, Thanks for the advice. I've been keeping my eye out for the amps you mentioned and I don't think I would hesitate to get one if the price was right.
Based on the feedback here, I've started a search for speakers simply to get a holistic view of what I want. To answer your questions, the room is 17X13 however it has a large opening (9ft) to a dining room. I listed to jazz, 60's psychedelic, hip-hop, ambient, pop and electronic. All of my music is digital. On occasion i will push them quite hard and wake up the neighbors. I don't have space to place them out 2-3 feet from a wall, and as a result, someone recommended the Paradigm studio 60's or 100's. I can't do stands because I have a small child.