I agree 100% about the weed burner, but, then why not build a proper design.
OP: If you want a small kiln, this book: https://www.amazon.com/Building-Your-Own-Kiln-Instructions/dp/477002973X includes a detailed break down for a VERY small but excellently servicable cone 10 reduction kiln. You can even easily reduction cool it with wood for enhanced surfaces.
I snipped this picture: https://imgur.com/FbmcjgN out of the amazon look inside feature. It's 18" wide by 36" deep and 20" high, not counting any chimney (which I'd recommend.
It fires similarly to a phoenix kiln but with a 20lb propane bottle, top loaded. It's a very good option for small spaces.