Hello,
I have the "Missouri Still" from the Colonel. It is a direct fire pot and I use propane to fire 3 "banjo burners". Each burner is capable of just over 200,000 btu's with the 30 psi regulator they come with. Of course, 30 psi into a commercial building would never pass any building codes, so check with your local building codes for compliance. I use 5 psi so my btu's are under 200,000 for each burner.
You should research or hire someone to calculate the proper about of fresh air needed to safety vent your flue gases away from your production area. Carbon monoxide can build up while oxygen is depleted. This can be very dangerous!
I have a fire box that directs the gases into the flue pipe which is 8 inches in diameter. It took time and effort to design the still, and the heating system, but it was worth it! I am very pleased with the full flavor profile that direct fire adds to my spirits!
I hope this helps! Send me a message if you would like more information.
Cheers,
Jim