I'll into the Holland burner.
This is one I have been considering,,,,
I'm guessing it's somewhere in the 30-40,000 BTU range, but I have an email off to mfg'r asking for sure.
I can control the flame somewhat with a needle valve, then hook it up to a gas vavle and thermostat,,,should do for cold er ambient temps. I smoke generator will likely be anough heat for most warm weather, as some suggested.
The smokgenerator, will be something like this, only with a electric hotplate under the wood/sawdust pan,,,
Then too, I may get a few other of the parts needed from there as well. Unless I can piece together the controller from elsewhere cheaper, it and some ohters will do.