Oxy / propane is what we use for brazing frames... it gets more than hot enough to cook your work and if you are running propane through tips designed for acetylene you will want to run a larger tip for brazing.

My rig has a #4 Victor welding tip on a 315FC and will heat areas to brazing temperatures in a few seconds and provides a very concentrated flame... heating larger areas rates a 5.

Advantage of propane over acetylene is it's lower cost, availability, and moving propane does not come with the issues you get with acetylene... you will use more oxygen with propane but this is still cheaper than running acetylene.