OK first of all Beej the specs you chose doesn't include a PSU, so we should use the case I chose which comes with a 400W PSU (It's a good quality PSU not one of those crap stuff)
The G620 is almost an equivalent to a i3 540 ( Which is good enough for video rendering and gaming)
The 430 being faster is true, so you should use that.
As for the hard drive, Seagate hard drives tend to run a lot faster than WD drives, I got my 1TB Black edition drive and compared it to a regular everyday Seagate drive and the results of the Seagate were a little bit faster than the WD drive (Mind was blown)
So it's safe to say that you should buy a cheaper Seagate and save money for other components.
Also, don't worry about Ivy Bridge, because there is no way you can build an Ivy Bridge rig for a low budget such as 500$.
EDIT: I just read that
Ivy Bridge got released !, So , I suggest that you wait a week or two for some prices and benchmarks so that we'll see if you can get an Ivy Bridge rig for 500$. Since the built-in IGPU is really fast for gaming and video rendering.
