Help building a decent budget gaming pic

I am currently piecing together my first gaming pc for about $600-$650 U.S. and I'm trying to find the best bang for the buck motherboard.
Parts I am thinking of:
And fx 6300 cpu
G. Skill ares 8gb (2x4gb) 1600 ram
Kingston v300 120 gb ssd
Seagate barracuda 1tb hdd
Gigabyte r9 270x gpu
Zalman z9 plus case
Corsair cx600m psu
I already have the case cpu and the psu but I'm not sure what motherboard I want to go with. I was hoping to be able to overclock the cpu to 4.2-4.0 ghz and I was hoping to get an atx but would be open to a micro atx. And I was hoping to only spend about $75. Any help on the motherboard or any other tips/suggestions on anything else would be nice too. I was looking at the gigabyte ga-970a-ud3p or the msi 970 gaming but they shot up in price the past week or so
will oc to a point ~ 4ghz should be easy enough, includes 120gb ssd, 280, 8gb ram, optical drive, 1tb wd blue, case, gold xfx (seasonic) psu - non modular but 5 mins in good cable management sorts that anyway.

Avoid those v300 ssds if you can. Will save you rma'ing the thing after a while.