Depends what you're doing with you're computer. An i5 and an i7 aren't going to be very much different if at all when handling games. If the processor is very important to you, and you are into all that heavy multitasking and video editing then the i7 might pull off better. The one you have on order is a better deal, as far as I see it's like this...
i5 vs i7 - $90 price difference (Depending on model, I'm comparing a i5 750 to a i7 920)
260 vs 5870 - About a $200 difference
Removing 2gb of higher speed ram - $-40
So you're looking at what should be a $250 more system thats 400 bucks more. If you're going to game then the one you're going to get is the better deal, but if you really need the i7 then I'd consider looking at another system because that's really not a good deal..