Should you be the one deciding that? @knutarn asked a few questions, we answered them. No need to deny him the information.
Get more RAM. RAM is cheap, if you're spending that much money on the processor and everything else, you might as well get at least 8GB. That should be sufficient for plenty of players.
I'm not sure on the price of that, but may I suggest an alternative? Dell R210ii - best bang for buck imo. http://www.dell.com/uk/business/p/poweredge-r210-2/pd