might be tricky leading wires to the motherboard when the motherboard is up top and the psu is at bottom. i have the exact motherboard and there are 2 connnectors at the top (a 24 pin and a 4pin) which means you will have to do some funky wiring or put the wires overtop the graphics card.
24 pin and 4 pin extension cables found on newegg for a couple bucks, there shouldn't be wiring over the video card, it blocks too much airflow.
With the 900/1200 cases from Antec, each has incredible fan control and airflow...so I shouldn't be too much of a problem I believe.
Does he really need a Quad? Only get a quad if you're going to be HEAVILY gaming. A Core 2 Duo will do just fine.
. You got to plan for the future. A game may come out that requires a quad core, you never know. Plus its just nice to say you have it.
Before you buy you GPUs be sure to take a look at the Radeon HD 4870 X2 and the Geforce GTX 280 cards. The Radeon HD 4870 X2 was put into Maximum PC's dream machine.