My setup is still the same.. the mono 200W amp on top of a PRS 212 with open back and a pair of celestion F12-x200. This is not an idela cabinet to match the low frequency response and being open back and 2ft from a rear wall, there is some mild hump in response around 120Hz that i take out with the OUTEQ in the FM9.
Overall tho, the amp has been flawless, and has absolutely zero background hiss/hum/buzz, and i noted above it compares extremely favorably against my $4000 audio amp from Classe.
Regarding your project, the IcePower 200ASC module has both power supply and power amp.This unit can actually supply the power for an additional power amp module, the (IcePower 200AC) . This second power amp only module is like $70... so thats pretty much $200 for a 200W stereo amp.. all other costs are wires, connectors and cases.
The two channels are completely independent so no "additional transformer" is required.. I think in this case knowing less is better than "enough to be dangerous" lol!
This is a very straightforward build. though not "easy" per se, just follow my recommendations and read everything many times and it should be fine.
fwiw ghent audio has a case for stereo operation similar to the one i used (link above) but it is not rack mount... There would certainly be plenty of space in a 2u rack for everything, with more than adequate room for fanless operation.