The i3-2130 will get the job done, and is probably equivalent to the 965 Phenom II, but for $40 extra, you can get an i5/Ivy Bridge quad core 3.1 GHz (3.5 GHz boost): »
www.newegg.com/Product/P ··· 19116506That $40 will double your cores and make a world of difference. This still comes in under your original $800 and is worth only a dinner out or a new game. I'd jump for the extra CPU power.
You're scraping the bottom of the barrel with that mobo. 1x SATA 6 port, one PCIe 2.0 slot (at x4 means not x16? - edit: although it has a PCIe 3.0 slot at 16x so you should be set for your GPU), two ram slots (have to go with 8 GB dims if you want 16 GB ever).
B75 is a budget chipset and probably not going to be produced in large numbers--I would avoid it and go stay with Z77 or the older Z68. I've had a bad experience with a sub-$100 board and like putting nice mobos in my preference.
Assuming you are aware of the limitations I mentioned in the first paragraph, go with it. While rated at only 450w, the PSU should handle the 6870 just fine, and has a nice 5 year warranty.
The 6870 is a great GPU at that price point. I don't know if I'd go with HIS, but the model is good.
The only thing you ought to consider via Microcenter is the CPU and possibly a CPU/motherboard combo (they routinely offer an extra $50-100 off if you buy them together).