That budget will pose a problem if you want to keep your preferred parts.
i5-2500K = $220
560Ti = ~$210
Win 7 OS = $100
That is $530ish already. $220 to get a case, Mobo, RAM, SLI-capable PSU, CPU cooler and OD = possible but quality will hinder the CPU and GPU.
Can you get to a Microcenter store? That would help save a little on the CPU and mobo since they offer discounts on a bundle.