The FX 8320 is the same exact chip as the fx 8350.
However, there is one key difference... the fx 8350 is a higher binned chip. the cream of the crop per se. Or the fx 8320's are the cast aways (two ways of saying the same thing really). This means that the fx 8350's on average will clock higher at better settings and will most likely last longer at high frequencies. BUT, if you just wanted to run the thing at 4.0 ghz or something like that, the fx 8320 should be able to do this with relative ease.
I ran my fx 8350 for 3 years clocked at 4.5 ghz on stock frequency, now its clocked at 4.0 running 24/7 in my esxi whitebox homelab. Its a great chip that offers you flexibility with what it can do.
I would recommend getting the 8350.