Which TOWERs work well CLOSE to the BACK WALL?

It seems to me that the best approach would be to get something with an active built-in woofer so you can adjust woofer output to room placement and boundary reinforcement. The Vandersteen 5A is in your price range, has a transmission line loaded 7" woofer and a powered and adjustable 12" subwoofer. The midrange and HF drivers are mounted on a minimal diffraction controlled baffle which should help the imaging and clarity in that range.

Audio Note

Thanks for all the comments.

Before this discussion, I was leaning toward Revel Salon2s. Any thoughts on those?

There's an old saying "the right tool for the job" and whilst the Revel Salon 2 is an excellent speaker, it is the wrong choice 6 inches from the wall.

Consider room treatment...Bass traps, first reflection zone absorption and buy what speakers you like that sound the best to you. If your room is untreated, you will never hear the true sonic potential of any speaker you choose. Generally, the closer a speaker is to the rear wall, the more perceived the bass is. All untreated rooms overload with bass and make the frequency response of the room far from flat. That issue robs your speakers, system of it's true sonic potential. Room treatments are the best money you can spend on a system...more so than the components themselves, imo.