I would use a broken wine cooler or a freezer, whatever is available. I just found a nice broken wine cooler on eBay for $10, should hold around 6-8 6qt tubs, which would be perfect for me!

Homemade is the best, with some flexwatt, a circulation fan, a Herpstat or Helix for a thermostat and some water bottles to regulate temperature is all you need!