Welcome to HWC mate
Cases are subjective, but I usually stay away from those that offer a psu.
I'd suggest the Corsair Graphite 600T, Fractal Design Define R3, Cooler Master 690 II Basic/Advanced
PSU: Any from Corsair, Seasonic, Silverstone or Antec. I personally love Corsair's AX & HX series, both are modular and the AX is Gold rated in power efficiency. Any unit around 600 for a high end single card or dual mid range cards, higher for dual high end cards.
Mobo: Gigabyte X58A UD3/5, ASUS P6X58D-E Premium are good choices for 1366, for 1156 go with Gigabyte's GA-P55A-UD3R or ASUS P7P55D-E Pro.
CPU: Intel Core i7 930 for 1366, for 1156 - i5 750
CPU Cooler: Cooler Master's Hyper 212 Plus (excellent performing budget cooler) or V6GT
RAM: You went with dual channel, the X58 chipset does tri-channel, so 6GB in 3x2 or 12GB in 3x4 is the way to go. Any DDR3-1600 kit from Corsair, G Skill, Mushkin or Patroit will do fine
Video: If your an ATi fan than stay with the 5850 and get a 2nd later on for CrossfireX, otherwise get the cheaper and better performing GTX460 1GB card and get a 2nd later on for SLI. If you want a single card solution, then get the 470/480 or 5870 (again if your an ATi fan).
Sound: Creative Sound Blaster X-Fi Titanium Fatal1ty Champion Series card or Auzentech Inc. X-Fi HOMETHEATER HD Audio card are my top choices.
Hard Drive: Seagate Barracuda 7200.12, WD Caviar Black, Samsung Spinpoint F3
DVD drive: LG, Asus, Pioneer, Samsung, Plextor will fit the bill
Good luck with your build