I was in the same boat. I think the 8320 is the way to go if that is the case. If you really don't want to overclock the i5 is a nice alternative but it is expensive. Overclocking requires a nice board and cooler too. The 8320 is the best cost for performance while still being futureproof in a sense.
Heres a quick build. You will still need an os and a cooler if overclocking.
PCPartPicker part list:
http://pcpartpicker.com/p/3skW8
Price breakdown by merchant: http://pcpartpicker.com/p/3skW8/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3skW8/benchmarks/
CPU: AMD FX-8320 3.5GHz 8-Core Processor ($149.99 @ NCIX US)
Motherboard: ASRock 990FX Killer ATX AM3+ Motherboard ($134.99 @ Newegg)
Memory: Kingston HyperX Blu 8GB (2 x...