I have a ton of torches and do a lot of heating, brazing and sweating. For general use, I'd go with a air/propane torch. They can also use MAP Pro also for a little more heat. The temp is not the whole story. The ability to pass heat to the item you're heating is different. Map Pro is quite a bit better at it. You can silver braze in literally seconds with Map Pro. Truthfully, for heating rusted, stuck fasteners calls for more heat. That's when a small Oxy/Act outfit is going to shine, of course, you can solder and braze with it too, but it's quite a bit overkill. You could go Air/Acetylene and be a little better off on heating stuck fasteners, but nothing beats oxy/act for that.
Lots of choices, but Air/Propane will do a lot.