Be careful with the sites selling mining hash rates, in a lot of cases it's a very small profit margin, and you'd be better off just investing that money into the coin. I'd recommend getting a second GPU, preferably a RX480 and just putting that in your desktop as long as your PSU cn handle it. It'll pay for itself pretty quick and you'll always be able to sell that card later on and get a lot of what you originally put into it out.