cool! i just ordered the appropriate risers from amazon. after reading the wikipedia article i realized that it would work ok. I just need to jerry rig where the cards will go in the case and make sure i don't surpass the power supply.
You can use more then one PSU.
http://www.youtube.com/watch?v=BviJjNYsIagBut I don't know why he is talking about grey it is black...