Would you recommend the HIS or Gigabyte 7870?

HIS Radeon HD 7870 2GB

http://pcpartpicker.com/part/his-video-card-h787q2g2m

Gigabyte Radeon HD 7870 2GB

http://pcpartpicker.com/part/gigabyte-video-card-gvr787oc2gd

This is my build right now...

http://pcpartpicker.com/p/Ggop

First, is there a reason you have the i5 3570 rather than the 3570k? The one you have selected can't (easily or effectively) be overclocked. The 3570k costs an extra 10 or 15 bucks and can be overclocked, with a good cooler.

Second, you'll want more than a 500 watt power supply. Find a good 650, at least.

As for the GPU, I'd go with the Gigabyte. I have a friend with a 670 with the same cooler, and he loves it. Stays cool, and he can't hear it without artificially cranking the fan up.

I'm not overclocking. What about an MSI gpu this one seems to have some better reviews. Will I still need to get a psu with more watts? 

http://pcpartpicker.com/part/msi-video-card-r7870hawk

500 watts is probably enough, honestly, but it's better to have more power than you need. An overloaded power supply can be dangerous to your components and/or a fire hazard.

Anywho, I have the MSI Twin Frozr 3 7870. The Hawk is basically like mine, but it's factory overclocked more and has a bit better cooler. Mine has been perfectly fine, runs everything I throw at it, mostly on the highest settings. That said, for that money, I'd grab one of these: http://www.newegg.com/Product/Product.aspx?Item=N82E16814202024

That's a 7870 XT, which is about 10% faster than any of the 7870s you've found, and costs about the same.

I think I'm gonna get the Hawk. Do you know of any PSUs that are reliable and is 600 Watts and modular as close to my price as possible?

https://pcpartpicker.com/part/corsair-power-supply-cx600m

Same as the one you had, but 100 extra watts. Extra 10 bucks, but a safe PSU is well worth it.

Thanks!!