Is this a good gaming computer and video render computer? BTW Building Myself?

Yes it is okey. But regarding the processor, there aren't many softwares and games that can fully utilize six cores. Infact most of them will give you the same results as in a four core processor. So you can save a little money there (if you want). And pick a good power supply as well, like a 750 or 800 watt, to give the system the juice it needs and future proofing for crossfire. And pick a 2.1 speaker system at least. You'll feel great listening to music. I give your system 8.5 out of 10, regarding it's an AMD system.