I find it hard to believe 50wpc is not enough. I run my CLS with less than 20 and it's more than enough power for high volumes... (driven either by 845-based SET amps, 47Lab gaincard, etc. )
The ML's don't do biamping or biwiring, but if you bridge your amps for mono operation, then you could probably have about 150wpc to play with. (bridging nets more than the sum of the 2 stereo channels). Still, there's not much reason to have that much power... unless your room is HUGE. Mine ran fine with 20 watts in a 24 x 16 x 12ish room with no problems. Smaller rooms are even easier. I had them running full range, but also had subs augmenting the low end.