That is a lot of speakers! I don't quite understand how all are being used. How much time is spent in 2-channel vs. home theater?
The Maestros are 93db sensitive. They get loud fast, and you probably don't want to hear this part, with almost any amp. Did you hear the speakers with any other amp at the dealer?
I am using Classe Delta Monos + Pre and combination is fantastic with the Focal Maestros. If you are not familiar, they are a 300W mono amp where the first 35W are in Class A. With how sensitive the speakers are, you are likely to stay in Class A for almost all of your listening. Your room is around the same size as mine.
You could buy three Classe Delta Monos for your L/R/C for less than your budget. I think you'd be very hard to beat the combination. They can be stacked and/or rack mounted without as much concern for their cooling. If you are doing a lot of theater you might consider upgrading your subs before dumping more money in amps. You'll likely have a bigger impact on the sound experience, at least for theater.
If you go the hybrid McIntosh route, I would make sure you can listen to them first. Their sound will be rolled off on the high-end compared to almost any other amp. I have not heard the Luxman MC10 so cannot help much there. I tend to prefer products design as mono if used in mono vs. a stereo amp bridged to mono.
I don't think you'd run out of driving ability with either as the Focals are easy to drive, but if you are looking for indication of the amplifiers driving capability:
The transformer is the Classe is nearly 2x as powerful as the Luxman. 1,250VA vs 2350VA and the Classe has nearly 3x the capacitance available (80,000μF vs. 250,000μF). If you are in US, you can likely get the Classe Monos for the price of one Luxman MC10. I'd recommend you audition both.