Rosebud tips are great for casting and all-around general heating.
As an aside- It seems hard to find nowadays, but MAPP is very nice if you need to juice a bit more heat out of a torch you normally run propane through. It's also got a more focused and intense flame cone, which isn't a real asset for casting where a bushy, soft flame is fine (like you get with natural gas),but if you find yourself doing some brazing or spot heat-treating for non-dental purposes, it's a treat. Almost as hot as acetylene, and without the acetylene fairies (floating soot) you get if you cut off the oxygen before the fuel.