Persian,
Trust the guys on this site, especially the monster and ultra techies: they know computers very well and are recommending the good stuff, not just what they prefer. If they say go with the DFI, do it. And ram is dam important too so don't buy that ram you mentioned. You should be able to get a really high end system for that price, so get what they have recommended cause then you won't regret it. Maybe look elsewhere if your supplier has limited manufactuers.....ie newegg, monarchcomputers.
Cheers.