Case and graphics is abit steep,
Thats graphics ain't worth it, barely any difference between the 5770, seriously! If you really wanted that, atleast get the vapor X version !
You don't need 850W, go for a HX650W (modular, neater and cheaper) and will easily let you run and overclock that set up.
Get two spinpoint f3s 500g set up in raid0 if you want great speeds and performance, because with the f1s in the 1tb version, heard they get noisy.
The Mega comes with 2 clips 100%

Also the TIM that comes with the heatsink is pretty good, no need for the AS5 unless your really need to drop an extra 0.7C-1C haha.
Be careful with the Sony dvd burner, its fast, got the same one on my grandfathers i5 build but it gets really noisy ! I'd suggest the Samsung version. It was nosier than all the system lmao.
heres the build for proof
http://forums.overclockers.co.uk/showthread.php?t=18102556
This is just my opinion guys, backed up with some pretty good reviews
Thats my lastest build, hope it will help