Have fun cooling 1KW of heat in a 2U server. Ah yes that's right, you can't.
Whole idea sucks in terms of actually being able to do what you said, and the fact it would cost about $1.5k a year per computer.
Cheaper than at home as proved.
But it is possible. If you are using 1kW then you will need at least 4U space using it or not (this datacenter maximum cooling capacity is 225W/U or 11.25kW/cabinet). It's not a home setup with a fan over the case. Plus if Supermicro makes these 2U cases with GPU support then they come with enough fans to do so properly.