If you have $2K - $4K on speakers for your room, you can probably borrow some from local dealers and test them out yourself. Personally, I probably wouldn't spend that much gelt on speakers in a "compromised" (less than optimal) setup. I think that you have already received some great suggestions above.
If you are planning to use smaller, stand mounted "bookshelf" speakers and place them against or near the walls you will probably want sealed or front--ported units. I enjoy a pair of Dynaudio Audience 42Ws in my office, and would also recommend a used pair of Linn Kans or maybe Triangle Stellas or Cometes.
Another way to go might be Ohm Walsh Micros. They sound very good, if a bit different but they would be a great option if you spend much time in your off center chair.
