Paradigm vs. Boston Acoutics

As far as affordability goes, I would do exactly what you are planning (I did the same thing as well).

I originally had an Onkyo/Integra reciever. I then went to a B&K Ref 20 pre/pro and a NAD 5 channel amp. And most recently I obtained a VERY nice Odyssey Stratos 2 channel amp for the mains and now use the NAD amp to power my center and rears. This setup works killer. My stereo music is now the best I've heard and the movies are even better than ever.

No matter what, I would get a sub if I were you. I don't know of many main speakers that can go below 20hz. It also takes a big load off of your amp and speakers if you get a powered sub for the LFE signal.

Paradigm. No question.

I have heard both and I must say the Paradigms are a better theater speaker and a MUCH better music speaker. I auditioned many speakers in this price range and ended up with the Studio 60's. If I were you I would consider getting the 60's as well. Since you are getting a subwoofer chances are you won't need the extra 5hz that the 80's offer. I use 60's in a room about 28x15 and absolutely love the soundstage.
You can also save some cash by getting the PW2200 sub. The Servo 15 is a top rated sub but I don't feel it is $500 better than the PW2200 (in fact, I don't feel it is $300 better).

In the end, audition both and get what you feel sounds better. Sound is 99% personal preference.

The only reason I didn't get 40's is because the price of speaker stands would push the price to the point where I might as well get floorstanders. That coupled with the fact that I have 6 cats who like to jump on furniture (ie: speakers) which dictates heavy speakers.