"...amps designed specifically for the speakers"? Nah, in general, the amps are selected specifically for the speakers and tend to be OEM modules from the usual suspects. The specificity lies in the DSP/voicing and one can easily do that externally
If you can feed them via the S/PDIF input (up to 24/192PCM), they can be treated just like regular powered speakers, albeit in pairs.
Ah. You want them to be a complete multichannel system. That's another story. :oops:
Not every time but, imho, it depends on why/how it is being done. I vaguely recall a story about a jazz remix created early in the multichannel era when a producer was asked "Why did you put the percussion in the back?" and his answer was "Because I could."
I have a fair number of unorthodox...