I want to know what are the best parts and brands that are for gaming and some editing in my price range of $700-750
all i need is a cpu,motherboard,ram and videocard.
also would a antec neo power 500w powersupply be enough? later on i might get a second graphics card for crossfire or sli.
If you're looking for pure gaming, stick with the E8400. It'll run cooler, has a higher stock speed and will overclock to a higher frequency. Most games will really benefit from the speed more than they would from the added cores of the Q6600.
Also, I'm not sure if you're PSU would withstand a crossfire setup... if you're not completely sure you're going to do crossfire, the X38 is overkill.
Looks like a nice build. I have the Q6600 and a Gigabyte p35 board. Very happy with both. If you haven't had a 4 core before, you're going to appreciate the 6600. There's nothing like being able to run multiple scans or encode a number of videos at the same time. It's a work horse.
The only thing I might up a bit would be the power supply....just because it's so damned important. If you're thinking of going CF in the future, I'd go for at least a 650w. A 750w would even be better. When you start pushing these things that's when the efficiency drops and voltage fluctuations can take place. Better to go big and not run the risk of blowing other major components due to a PSU failure. (with all due respect to pcgamer) :-)