Hello Carey,
If you plan on keeping the HC's, the MIT 850 Triads is a must. I bought my pair used on this site.
The cables will do a dramatic change in sound quality for these speakers.
I have owned my HC's for about 5 years now and I'm very happy I bought the cables.
The cables really are network interface cables. They were specially designed for the HC's. They weigh about 25 lbs for the pair (8 feet long). They break the signal down to having one connection to the amp and has 3 output connectors to the speakers, low, mid & high. You can then remove the jumper connector. The owners manual suggest that going with the Triads is the best thing to do.
They are pricey but well worth it for what they do for the sound.
I payed $2500.00 for my pair used, they listed for $9500.00 when they came out.
With the size of your room I would think you will need more power also, maybe not? When I had my 4BST hooked up they sounded very good and would play loud if I wanted to.
Many good amps out there that will work.
Please try to read the Stereophile review I spoke of.
It is also suggested to have Spectral equipment with these speakers. There have been many forums about this subject also.
I can recommened the MIT 850 Triads without hesitation.
If you buy the cables you can change amps and still will have the proper cable to go with them.
I know some people do not believe cables can make a difference and they are intitled to their opinion.
Since I own the HC's I have first hand experience with there sound.
I would suggest you try to get a used pair (10 feet long) if you can.
The cables (interface cables)really can only be used with the HC's (IMO).
Send me an e-mail if you want to talk about the cables and amps in more detail.
Respectfully,
Joe Nies