I won't change your case, since that's usually personal preference.
(it's modular and comes out cheaper with rebate!)
if you aren't OCing, MB
if you are OCing
if you want DX10, GPU
if you want 10.1. I'm not sure if there's a major difference or not between DX10 and 10.1, but I always go newer. I'm thinking they'd be pretty comparable. I'm thinking you'd gain some performance with a 1GB over that 384MB you listed, but I'm not sure. Someone can offer assistance here.
(Holysky posted it first! Beaten!)
With rebates, this comes to ~$400 I think. I didn't factor in shipping.
EDIT: If you don't want shipping on the PSU, this
would be fine; and no rebate hassle with that either. And, I said I wouldn't, but here's a cheaper case
if you wanna do penny pinching.