I live where we heat with delivered propane, and this is the
first I've ever heard about "different mixtures of propane".
Propane is propane is propane, as far as I know, and my dealer and
I were planning on having me use the same propane for my torch
(when I get it) that I use for heating.
I use propane right from our big tank out in the yard, piped into my
studio by a professional via copper tubing. I have a shut off valve
and the regulator attached to the wall next to my bench. This is
M'lou Brubaker, Jeweler