That hasn't been determined yet. I will wait until I have finished production samples of the SuV-Gun to make the final gas flow orifice size to set the flame distance appropriate for the torch. I know this is a complicated answer, but I'm hoping to give you an answer that is helpful. More gas flow just makes more flame, too much flame cannot be used safely indoors. Now to directly answer your question directly, I expect it to be a 1/4 to 1/2 less gas flow (300,000 to 200,000 max BTU).
The main thing I want in the Su-VGun is a controlled, very hot, and focused flame that completely consumes all the fuel being expelled by mixing it with the maximum amount of oxygen available in the atmosphere. Fully burned propane produces heat, water and CO2, all fully suitable byproducts of a flame that you would want to use in searing your meat. That is essential in the close work of searing meat with a short flame on a granite, stainless steel, or other non-flammable surface in the kitchen, or on a grill outdoors.
The reason the combo is the most popular selection that people are requesting is that they want the best of both worlds. They want the big rolling, long barrel and flame, for lighting their grill, but the notion of 2' of fire rolling out of the long-gun just isn't a good idea for use indoors.