If the original poster is still interested in a multi-channel power amplifier, I have used Outlaw Audio as a power amp supplier. Outlaw has a wide range of seven channel power amplifiers with per channel wattage of 75, 125, 200, and 300 watts. They also have a new 5-channel 180 watts unit. Outlaw's amps are conservatively rated amps with basic features at low prices.
I use 6 channels of their 7075 amp (I have a relatively high sensitivity open back speaker set-up) with my 3-way DEQX processor configuration.
Once a year they have a B-stock sell (blemished or repaired units with full warranty) which can lower the acquisition cost if you are lucky enough to time your purchase just right.
https://outlawaudio.com/products/Jim Griffin