I recently had the chance to work along side with Richard Blais, he of Top Chef fame, as well as his excellent burger restaurant in Atlanta, Flip. He has been touring the country a lot, touting a new product -- the first sous vide machine available for home use, called the Sous Vide Supreme.
I asked him what the temperature range was -- and he said 203F. I was more interested in how low it got, for possible cheesemaking, but he wasn't sure. I've checked
the specs -- it ranges from 41F - 203F.
The capacity is 10 liters, or 2.64 gallons.
This is an expensive option, but its precision is fantastic, and it has other uses (sous vide cooking, of course). However, that precision is based on having water in the bath. I can't see why it wouldn't work with another liquid, but it is possible that the instruments are just calibarated for water.
I don't have one, but I thought I would let you all know about another possible option.