You'd have a better machine if you went with an AMD build. In fact, I don't think you can get all of that under $800 with Intel. Off the top of my head, I can tell you an i5/5770/USB 3 build will run around $900.
Here's an Intel build:
Mobo: Asus P7P55D-E Pro
GPU: HD 5770 $155 after rebate
RAM: Corsair XMS3 2x2 GB 1600 mhz CAS Latency 7
HDD: Samsung Spinpoint F3 500 GB
Case: Antec 300
PSU: SeaSonic 850W
$110 (if you want to Crossfire later)
Optical: Cheapest SATA DVD burner
Here's a better AMD build for less:
CPU/Mobo: X4 955 and Asus M4A79XTD EVO
$256 after rebate
GPU: HD 5850
Rest the same
Total: $877. Since they're both over $800, the only real option is the AMD/5770, which totals $762.
EDIT: Actually, you can get an AMD/5850 build for under $800. Use this X3 425 and Asus M4A79XTD EVO
combo for $160 (after rebate) instead of the one above. Total is $781.