Spend the extra and get the 3770k, its worth it in the end. the 8350 just dosn't hold it's own.. unless you are doing some media production. Mine use to kick add coverting video to other codecs where my 3770k is horrible at it, but it's completely flipped in Gaming.
Wanderer is right, if your going to have the background processes, the 3770 will not lag on you while gaming.
Depending on the site, an 8350 trades blows with a 3770k in multithreaded tasks, and holds with the 3570k in gaming. It's single threaded performance is pretty weak though.
Look at pricing between the three platforms and see which feature set fits you best. I would personally recommend a 3770k or an 8350 for heavy workloads. The 8350 will save you quite a bit of cash by the time you total up the CPU/MOBO.