A pair of MMGs and a pair of Rythmik or SVS subs (all direct, all in-home trial) makes for a great, full-range system that might fit in your room without dominating it. Similarly, a pair of smaller Ohms with subs might do the trick (tho at a cost premium). Either way, pairing the subs/mains with appropriate electronics makes it easier to optimize this approach - I'm a fan of Audyssey (or similar) to ensure smooth response thru the "hand-off" from sub to main. The good news is that the MMG/sub combo plus a suitable amp (Harman Kardon HK 990, for example) can be had new for well under $4K, well within your budget.
Just one more idea to kick around.
Just one more idea to kick around.