Get a H67-itx board (Foxconn ($75) and Intel ($125) make them) and a $205 i5-2500. Since the H board won't allow overclock anyway, don't waste time on the K-series, and use the standard intel cooler. Change to 8 GB of RAM instead of 4 GB for the same cost. (Mushkin enhanced Silverline are $82, or G.Skill is $80)
You spend $20 extra for the intel motherboard, but you don't need the CPU cooler (the intell one is not that loud), so you save $13. you could also step down to the basic model of the GTX460 or the HD6850 for $180 instead of $200., saving $20 more, then manually overclock the card instead.