I'm looking to build a quiet/silent office PC mid-tower case. I'm thinking i7 CPU and a fan-less GPU card. Probably the most intensive activity would be HD video editing. The cases I've identified in no particular order are; Fractal R4 Gigabyte Cupio 6140 Corsair 550D Antec P280 Any opinion on these cases is welcome. Other options too. Personal experiences preferred.