I know Xantech has a multichannel amp with IR controlled volume built in, I only used it once and it worked fine.
The reason I only used it once is because I usually use the bulletproof Sonamps, it had nothing to do with the quality of the Xantech amp.
I needed IR volume control in the amp for a really bizarre retrofit with walls of windows, mahogany panelled walls, and coffered ceilings where I couldnt cut VCs into the walls. I used MX-800 remotes and surface mount Canton Plus speakers and the Xantech amp.
The one I used is rated at 12 channels by 35 watts, but I think they have other models now.