Everything seems fine but you might want to look into buying a a new cooler for your cpu something like the noctua NH-L12 (it's low profile) so you can get a decent oc. I heard people running at 4ghz with the stock heatsink and staying around 50c though. If I am correct the r9 270 is a rebranded 7850, in that case you have the fastest gpu for that price range. So you should be able to run 4x IR and probably some AA without any fps drops due the the gpu. I think everything should fit in that case without to much of a problem. But that system should pretty much play anything out there.
Intel i5-4690k @ 4.6 GHz | Gigabyte GTX 970 4GB G1 | 8 GB DDR3 @ 1600 MHz | Windows 10 TP | Dolphin 4.0-6811