I have a 30 x 50 x 13 steel building in central Arkansas that I have been looking at the possibility of heating and cooling with a geo heat pump. I am fortunate in the sense that there is a 5 acre pond behind it that's roughly 10 to 15 ft deep where I would be laying my coils. Based on what I have read, the fact that it's a poorly insulated (just radiant barrier) and a ton of thermal mass, I would need to oversize it to around 3.5 to 4 tons. I found a FHP EV048 that I can get pretty cheap but I am trying to determine if this is something I can reasonably DIY. Also, based on a 4 ton unit, I have read that I would need a minimum of 1000 to 1500ft of cooling pond loop. Does that sound about right?