The fish fryer i use is a bass pro shop brand, it cost 40 dollars in the store at their chicagoland location. Here's the link to it:
It has a pretty intense heat output, and can melt about 15 lbs of lead in about 10-15 min. I don't know about propane usage yet, I've been able to smelt 150 lbs of lead in the past few days on a fresh can, that doesnt seem close to empty. I'll let you know how much I'm able to do before the can runs out.
I bought a pressure cooker from goodwill for about 3 dollars and its built pretty well, though the plastic handles have all melted and broken apart so there are only screws sticking out of it. I think the most i've had in there is about 70 lbs, and the stand holds up OK. I could probably fit about 100 lbs of lead into my pot without overflowing, but it'd be close and I have no need to pack it that full. The stand kind of wobbles but I'm not alarmed by it. I probably could have put the screws on there tighter when i assembled it (they're phillips with a nut, not hard to do), and I'll probably end up doing just that before I smelt next. I don't have a thermometer, but would assume it gets pretty hot due to the melting time.
The setup seems to modestly conserve heat energy with the shielding around the burner, and you can be standing right next to it and not feel the heat unless you're directly down wind (not like the saturday's camp fire), which is also a good indicator if you're inhaling vapors.