Working from the ground up:
CPU + mobo: Newegg.com - Computer Parts, PC Components, Laptop Computers, LED LCD TV, Digital Cameras and more!
Memory: Newegg.com - G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL9D-4GBRL
PSU: Newegg.com - SeaSonic SS-500ET Bronze 500W ATX12V v2.31 80 PLUS BRONZE Certified Active PFC Power Supply - Power Supplies
Hard Drive: Newegg.com - SAMSUNG Spinpoint F3 HD103SJ 1TB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
+$100 for OS, total comes to $423
Spend whatever you have left on a video card BUT, from reading your posts, you seem hung up on what a lot of people are, which is video memory. A 768MB GTX460 will wipe the floor time and time again with a 1GB 8500GT, even though it has 256MB less video memory. The only reason to ever have larger amounts of video memory is if you are running very, very high resolutions in graphically intensive situations, such as HD gaming at the highest settings on the latest and greatest games, otherwise there is no reason what so ever to spend money on what is a gimmick and a marketing technique.
The build is better as you get a better mobo + CPU, but for cheaper. Your processor has 2 extra cores, so in games, video editing and multitasking, it will perform much better, those 2 extra cores will make a hell of a difference.
You get dual channel, rather than triple channel memory. The memory you picked is for Intel socket 1366 boards whcih supports triple channel memory, rather than every other current socket, which all support triple channel (including AM3, which is the socket you are on with this build)
You upgrade that poor excuse for a power supply for one of a much, much higher quality.
You get a much faster hard drive, the one you picked is designed as a storage drive, not for a main hard drive, which would massively impair boot speeds and load times for all programs.
I would also point out that your case is too small for any of this to go in, as it isn't able to use full ATX components, which all motherboards posted so far are, and which your 5770 wouldn't fit in.
Newegg.com - NZXT GAMMA Classic Series GAMA-001BK Black Steel ATX Mid Tower Computer Case
Newegg.com - NZXT BETA EVO Classic Series CS-NT-BETA-EVO Black Steel / Plastic ATX Mid Tower Computer Case
either of those would be better choices, however I would strongly recommend AGAINST picking a case before posting it, when you get a cheap case, there is a reason for it, usually poor layout, poor cable management, small size and low quality materials