-64GB is pretty small for an SSD, and 128GB is well within your budget. I'd bump up.
-A 7970 or a GTX 580 are both overkill, but that doesn't necessarily make either one a bad investment. Early benchmarks point to the 7970 having a modest advantage over the 580, so if you're going to go with one over the other I would take the 7970. That said a 570 or 6970 would be more than enough, and both are good cards to SLI/Crossfire later.
-If you're going to double up on graphics cards down the road, you'll want a slightly beefier PSU. Another consideration would be a modular power supply -- the ability to remove cables helps eliminate clutter & improve airflow in your case. Check out the HX650 (no SLI/Crossfire) and the PC Power and Cooling Silencer Mk II 950W (yes SLI/Crossfire).
-You'll want an aftermarket heatsink like the Hyper 212 EVO to overclock your i5-2500k.
Thanks man. I'll look into your recommendations. The reasons I didn't have a bigger PSU was because I was just gonna wait until I needed to SLI/Crossfire before getting a bigger one, but I might just get the one you suggested.
As far as the heatsink goes thats the one I was looking at buying down the road when I start looking into overclocking.