upgrade suggestions please

I've really enjoyed my NHT Super Twos for the past 5 yrs., but now looking to upgrade, as other components within my system have also improved, and want to maximize their potential. Here's the criteria: our music room is dedictated, but a bit limited in size. Listening point is approx. 10', speakers toed in slightly. WAF requires that we maintain a small footprint w/ a slender black design sim. to the Super Twos. I would like to continue w/ a full-range tower, as opposed to bookshelf/stands w/ sub. Our budget is probably in the 1500 - 2k used market range. Any and all audition suggestions are most welcome - thank you.