|"I kept looking for vid cards and I kept coming back to the 4650, so that's what I got"|
Not a horrible graphics choice, especially if you found one with DDR3 rather than GDDR2 or DDR2. You probably could have done better in the same price range though. The HD 4670 is a much better card for about the same price & the Geforce GT 240 with GDDR5 also falls into that price range...about $60.
Graphics Card Hierarchy Chart
As for the RAM, I agree with kuwese. Look for DDR2-1066 that runs at 1.8v - 1.9v. Beware so-called "gaming RAM" that requires up to 2.2v. If doesn't perform any better & the higher voltage is generally necessary because the RAM is lower rated RAM (DDR2-800 for example) that is factory overclocked.