This isnt a good choice of case to build an M-ITX gaming rig into,at least not without some modding.
It has little to no airflow and will cook higher end components.
In it's stock form I think you'd get away with an i5 750/760 and a lower power gfx card such as a 5670,any more than this and you'd be looking to mod the case.
The Q11 which is the soon to be released update to this case has the same footprint,but with "slighty" better cooling potential.
Other than that it the usual SG05/6/7 and the Lian-li Q-08.
If you dont fancy any of those Langear also has an m-itx case in the works although there's no actual release date for it yet.