The CPU Cooler, PSU are definitely going to be quiet.
The GPU I suspect will be quiet because it has two fans/a good looking cooler, but can't confirm as I haven't seen a review for it nor heard it myself. And a factory OC'd 7850 should be able to meet your Skyrim and BF3 requirements.
The HAF 922 wouldn't be my first choice for a case that was meant to house a quiet system. But aslong as the components you choose are quiet and don't need much case cooling, then you can reduce the speed of the fans in the HAF 922 and overall it should be quiet.
I'd recommend changing the PSU to the Seasonic 620W. It's from a much better brand since Seasonic is one of the best PSU manufacturers and it wil give you a bit more juice for doing crazy things with your system. For an extra $10 over the Rosewill 550W model, it's a no brainer. I don't think you'll have an issue with the power output of a 550W PSU but the Seasonic name is worth it. I've got this same PSU in the rig in my signature and it's been rock solid.
Alright, thanks! Unless there's any other objections I'll get right on to ordering parts. I also checked a game benchmark and it looks like I'll be able to run Battlefield 3 close to if not at ultra settings so definitely exceeding my expectations.
I would say that the Capstone 550W is actually better than the Seasonic M/S12II Bronze platform. It is more efficient; 80Plus Gold vs Bronze. It regulates better because it has independant voltage regulation, the Seasonic unit has group reg. Ripple and noise suppression might be better on the Seasonic, but it's not like it's bad on the Capstone.
Build quality, Seasonic again is probably slightly ahead.
Fan noise; now then, this is where the Capstone wipes the floor with the Seasonic.
The Seasonic M12II Bronze 620 uses an ADDA AD1212MB-A71GL. Which has a maximum speed of 2200RPM, which it reaches on full load. It's only really quiet until probably a 350W load. See here for a fan curve graph: http://www.xbitlabs.com/articles/cases/display/seasonic...
The Capstone uses a Globe Fan RL4Z B1402512M, 0.30A which has a maximum speed of 1200RPM, but tends not to go above 1000RPM, even on full load.
Ah, ok. Well really what'll matter to me most is the noise (nothing kills a night of potential fun like a baby suddenly waking up at 1 in the morning) and efficiency. If I get a bad PSU build, I'll just take it back and play on my current crappy computer until a good one arrives.