With that motherboard, you could get a slightly cheaper MB and an I7 920???
But an i7 is a waste of money (in my opinion) unless you're doing tasks that utilize the hyper-threading capabilities.
And regards to the 5870, a 5850 matches and surpasses it with a slight overclock that takes about 15 minutes to set up, if that.
Sorry about that, must have stopped selling it. Probably stick with this ramRam link gives me "Sorry, this product is currently not available" ?
Other than that another good build to think on!
Thanks!