Monoprice is good stuff. If they have something you want, get it! Remember, a LOT and I mean a LOT of brand differences and pricing is 100% marketing. Many times' when you look under the hood, or case in this instance, you find many amps are almost identical. I would never spend a lot of money on an amp if you can get the same power and features (whatever they may be) for less money. High end amps are kind of like high end speaker wire. More marketing than actual technical performance. Remember the Big Three, 1- Speaker placement and toe in or out, 2- Room Eq and 3- room treatments will give you huge massive benefits compared to any amp, pre-amp, wires, interconnects etc. But it is a lot harder to do the big three than just running out and buying the latest new piece of the same old gear hoping that it will create magic in a system. Gee? How did I get so off track? I must be getting senile!
Jonfo has good advice as he is 100% custom and scientific in his home system. It is crazy good.