what type of GPU would fit well into this build?

Solution
If you are not buying until october, when Vega 490 is supposed to be out, your question is premature. Ofcourse, a single, most powerful card you can afford, is always the best solution. So, as of today, i woudl eb looking at a 1070, not two 480s.
If you are not buying until october, when Vega 490 is supposed to be out, your question is premature. Ofcourse, a single, most powerful card you can afford, is always the best solution. So, as of today, i woudl eb looking at a 1070, not two 480s.
 
Solution
AMD can't really even begin to compete with Nividia's new line up. I would also follow suit and say a 1070 or 1080 is a far better choice. Personally I would go with a 1080 just for long term performance.