ADDITIONAL COMMENTS: Trying to put together a system that I can use for the next 3-4 years with options to upgrade. Not too sure about my choices for RAM and mobo. Also from what I've read the i7 930 will be released in about a month and will be replacing the 920, would it be worth waiting for?
The 5850 should be considered the entry point for DX11 gaming at 1920 resolution with "today's DX11 games". No way to tell as yet but as games start to more fully integrate DX11 features, I expect it may start to struggle with the more demanding games that should start arriving come Xmas 2010.
All the 930 will do, from what I've read, is bump the clock speed. Since you are planning to overclock, the only thing you'd be waiting for is the ten dollars or so price break on the 920. That ASRock is a good mobo. As for the memory, I have, and have had in the last few builds, OCZ memory, and I like them. A lot of people prefer the recent gskill's ot the corsairs. But OCZ is good too.