All the ATC designs from the 20 on up sound alike - so if you don't like one you've heard then don't waste more time. They are great for crystal clear dialog even with loads of stuff going on. Dynamics and loudness whilst maintaining low distortion levels is what tends to differentiate them from others - so you'll squeeze quite a bit more excitement from a dynamic movie soundtrack than usual. I suspect you could do passive 20's all around and a JL F113 sub - all used for something close to your target price. The ATC 15" sub is roughly three times the cost of a JL F113 and would definitely be overkill if this is not your main system. You'll definitely need to find a really tight (low Q sealed box) sub if you go with those speakers though or it will probably end up as a dogs breakfast.
Speakers for HT/2 channel
Broad question, but if you were buying a speaker setup, 7.1, for HT only what would you buy. Using Integra 9.8 pre/pro with cary amps. Stereo quality not important as I have a dedicated system. Room approx. 17x14 with 12 foot ceilings. Would likely buy preowned. Budget $8000 total.