You can go pretty high end for $2000. Do you need Monitor(s) included in that?
Okay then:
I'm not sure what you want for monitors but you can get a decent 1080p 24 incher for $180 which still lets you build the second machine and is quite high end.
If you need two monitors and you are only doing medium level gaming you could drop the GTX 680 and go to a 7870 for around $360 instead giving you room for 2 monitors in that price.
You could get a cheaper case and save $50, you could aircool and save $40, could drop $40 and get a slightly lesser motherboard etc, but I was trying to use up the whole $2000 suggested.
2K is quite a bit of cash - so you can definitely afford to get good stuff. When are you looking to purchase? The rumor of Ivy Bridge coming out at the end of the month might be worth the wait if it proves to be true.
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