I've owned the NHT SuperZeros, Infinity P362s, and many DefTechs.
I like them all.
Since you don't need LOUD and BIG SPEAKERS, I would not recommend any towers.
So that leaves you with NHT & Deftech. Of course, there are many other brands like Aperion, which offers a free 30-day trial.
Recently, Home Theater Mag reviewd the NHT Absolute Zero book shelf speakers. The 5-point average of on-axis and +/- 15 degrees off-axis frequency response from 200Hz to 10kHz was +/- 0.93dB, which is EXTREMELY FLAT and awesome!!!
Normally, we expect something like a +/- 3dB, so to get a +/- 0.9dB is absolutely amazing. I guess they didn't call it the "Absolute Zero" for nothing!
So, if I were space-limted and cannot go with something big and loud like towers, I would get the 5 NHT Absolute Zero and one NHT Subwoofer for 5.1.
I would not WASTE any money on more than 5.1. Personally I've done 7.1 and it makes absolutely no difference to me. Remember, the majority of a movie soundtrack is for the front L/R/C. Only a small percentage goes to the surrounds. The primary purpose of surrounds is for ambience effects and panning effects. A 5.1 system will do just fine, especially if you don't have a 10,000 cubic feet room.
A rear center is just ridiculous!
NHT Absolute Zero: $175 x 5 = $875:
NHT small sub for $350:http://www.amazon.com/NHT-Super-110-...5886213&sr=1-2http://www.amazon.com/NHT-N-AZB-Abso...5886159&sr=8-1
Total = $1,225 (free shipping from amazon)
Or for an additional $100, get a bigger sub:http://www.amazon.com/NHT-B-10d-Powe...5886213&sr=1-3