They are quite inexpensive to make. Just buy something like this: http://www.jegs.com/i/JEGS+Performan...80065/10002/-1
,assuming you have a chevy engine, and mount a radiator in front of the engine with an electric fan. Then get a gauge panel and mount that wherever you would like it. Autozone sells a nice little gauge set that has water temp, volts, and oil pressure for like 20 bucks. Them all you need is a battery and a gas can and you're set. The total cost is only about 150 bucks if i remember correctly, maybe 200 at the most. And to answer your question, i haven't seen anyone who rents them but you never know.