If you already have an Intel Platform, go wit hthe i5.
If you are building new from scratch, DrewWhoo's recommendation is good. Get a 970 series motherboard, a FX 6300, CoolerMaster Hyper 212 EVO cooler will let you overclock it like a champ, and at the time of this posting NewEgg had the OCZ Mod extreme Pro 700w on sale for $65 ... that's 50% off. Thats a steal for a good power supply.