If you can handle the initial expense I think the post with the ground source heat pump is a good way to go, get down about 100 feet and the temperature is nice and cool.
You are talking about geothermal correct? I looked into that when I was doing my setup. This is a good option to cool your house. Unfortunately when you have a bunch of miners pushing hot air at a rate of 5.6CMM each, plus an outside temperature in the mid 40s the heat exchanger simply cannot keep up.