IMHO I would think the 7100 would be more than enough for a home theater set-up. The only improvement with the 770 is at extreme levels you would be less likely to “clip” and send a square signal to your speakers and cause damage.

As far as filling the room you describe with sound 100 watts should do that fine and as loud as any normal person would want to listen to. I may be wrong (and I’m sure I’ll be corrected if I am ) if you want an amplifier to play twice as loud as a 100 watt amplifier most people would think you would by a 200 watt amp. However it is my understanding that if you want to play twice as loud you really need a 1000 watt amplifier. Outlaw rates there amps with a lot less of a curve than a lot of other manufacturers. 100 watts per channel is a lot of power on tap. If you remember back to the late 70s early 80s it was very common to find nice equipment rated at only 25 to 50 watts. Hope this helps

Lasher