Bernzomatic is a company dedicated to combining heat and craftsmanship. Their products are useful for welders, as well as smaller heat-based crafting projects. If your work involves fire, then Bernzomatic is the way to go.
It depends on the product you're using. The products on Homelectrical's site use Map-Pro, Propane, and Butane, but some Bernzomatic products use oxygen cylinders.
Why does my torch go out when I turn it upside down?
It probably means that your torch doesn't have a pressure regulator. In these torches the liquid propane runs down the neck of the torch and douses the flame.