All - we have this waterer: https://www.amazon.com/gp/product/B016AO5GAI/ It's made by RentACoop, and we're very happy with it. Now we're looking for a heater set up for it. The Amazon page suggests we get the RentACoop heater base but I have no idea where to find it. I would appreciate any suggestion for a good heater for this waterer. (Not looking for a DIY solution at this point, thank you.) Many thanks!