Re: $800-$900 Build for Friend
Man, you're hooking you buddy up big time! He's going to have a really nice gaming rig. I'd say go with a Core i5 750, a mid range mobo, and 4GB of DDR3-1600 Cas 7's. I'd go with a Corsair 750W. I'm a big fan of the Cooler Master HAF's. Is he going to overclock? You seem to know what you're talking about, but if you want some specific product questions or help with specific parts, just ask.
EDIT- Come to think of it, maybe 8GB instead, since he has some cash to spare. I'm sure we'll see the day you'll use more than 4GB relatively soon. Maybe even the Core i7 860 for socket 1156?
Back on being mobile - ASUS G551- 15.3" 1080p - Core i7 4710HQ - GTX 860M - 16GB DDR3 1600 - 512GB Samsung 850 Pro - Steam ID: TheOtis