Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.
If it's going to be kept for 4 years I'd go for a quad, more and more games are multithreaded now. Though saying that it depends on the games you play, if it's just FPS I'd probably go with a dual core.