I am currently using a Q08 as a back up pc. I am considering converting it to a gaming system, and it looks very good for that purpose. Take a look at the red version. I have one, and the color is stunning.
It will hold the longest of graphics cards. I suggest using one of the newer 28nm based cards which will eliminate any cooling issues. With your budget, a GTX680 is good, but a GTX670 will really be all you need for a single monitor.
If you go crazy, even a GTX690 will work.
The case will hold a standard ATX psu. 650W should do it. Because of the limited room, I suggest a modular psu.
The seasonic X650 would be good.
I would plan on using only a single large 250gb SSD if you can. It should be sufficient for the OS and more than a dozen games. Add a hard drive for overflow if you must.
One issue with the case is the limited height for the cpu cooler.
After research, the best one I can find that fits is the tr AXP-140.
Noctua now makes the NH-L12 cooler which I think will fit.
I love the noctua fans, so check that one out. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
The supplied 140mm intake fan delivers plenty of airflow for both the cpu and the graphics card.
Some will try to fit a liquid cooler into the case, but the radiator will take out one of the supplied cooling openings and screw things up by delivering heated air into the case. That may be good for the cpu, but not for the graphics card. I don'r think it is really necessary. If you oc a 2500K or 3570K to 4.0 or so, you will have no heat issues, and that is plenty fast for any games.