Gigabyte or cooler master casing? & gc question..

I'm thinking of building a rig with the following specs :

core i7 920
motherboard P6t
cpu cooler - noctua u12p
cooler master real power pro 850w
xfx gtx 285 black edition

& I'm wondering whether to get a gigabyte 3d aurora 570 or a cooler master storm sniper. And if I want to save some $$ and opt for CM690 instead can all of those fit in? Besides.. should I go for a cheaper graphic card like galaxy/palit 285gtx instead? The price difference between XFX and palit is around $USD70-80(in Malaysia) .. thanks

yea i came accross the antec 900 while doing more searches. It's so smexy lol. But its availability is limited and antec 900 price is double that of CM 690 lol. I honestly don't know if I should spend that much on a casing as I won't be carrying it to a LAN party to show off or something... about the other items I've considered many times and I find it a real dilemma to choose between options. I think I'm having headache