If you are handy and have some time, you could build your own propane smoker with a temperature controller. On mine I built it with the option to use an electric hotplate in it as well, that is easily controlled with a cheap STC1000 PID controller. This way I can hold temperature as low as just above freezing (when it is freezing cold outside) up to really hot. The cost of the actual smoker will vary with how you build it, but I would say that the guts of the propane burner, with the control valve, and temp controller will run around $200 with parts bought off ebay, etc. For the electric controller with the hotplate, about $40. Being able to control your smoker temperature with very little babysitting is awesome. Let me know if you are interested in seeing my set up, I can get some pics.