I am considering purchase of Adcom GFA 5500 Power Amp and Proceed AVP Preamp. Can anyone suggest some options as to which speakers would go well with these? Here are my requirements/Questions:

* Preferably under $1,200.
* It buying used speakers a good idea?
* I am interested in traditional 2 channel, stereo setup only.
* Need a good, clean response.
* Prefer 3 way speakers.
* I listen to mostly Western classical. However, I need accurate reproduction of Pink Floyd recordings also.
* My listening room size is 21ft x 15ft. The ceiling is 14ft high. It is a family room and does not have a door - it is connected to the kitchen.

I currently have Polk Audio RT7s (owned them for past 6 years). For the price I paid, I like them. However, I find they lack mid-range clarity and the bass is a bit boomy. The new speakers I buy should not be deficient in these areas.

Any help is appreciated.