Bakua :
I don't think it'll beat Intel, but price efficiency is what AMD's good at. I'll probably go with the i5-6500 build Hls has listed. Is there any (real) difference between the i5-6500 and i5-6600?
Marginal. Not worth the premium. Between the 6400 and the 6500 it's a no brainer for teh extra 500Mhz for a few bucks.
Regardless of how good Zen turns out, both the builds i listed are a safe bet, though the xeon may prove better in the long run as it has hyperthreading and games are going to become better threaded. Also, if you ever intend to SLI and/or stream gaming, teh Xeon wins hand-down.