What are some good budget options?
I wanted to get the Gigabyte GA-H110M-S2HP, but unfortunately, Amazon doesn't ship that to Peru,
Well smuggle one back in, I'm not sure on any other decent budget boards with USB 3.1, you can use newegg power search to at least find a board, just look for 1151 and the USB 3.1 options are at the bottom.
What about PCIE cards? Not sure if they're an option or readily available, but something like this might do the trick.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813998030
Which cpu do you wanne go with, and what is you exact budget for a motherboard?
You are better off getting a board with dual channel memory and able to to overclock well. Save some extra cash it will be worth it.
Their are other alternatives other than amazon.