@
mixteup, I use didymium glasses, which block "sodium flare" - let's you see through the flame. (edit: scarlson beat me to it! I got them on Alex's recommendation) I use traditional Oxy-Acetylene. I know a guy (Jim G., the guy that made the trail calculator shown above) that has an oxy-propane set up using a refurbished medical oxygenator he got for about $300. Now his oxygen is essentially free, propane is cheap and easy to get. The flame's not as hot as OA, but "hot enough" for brass even by conventional standards.
For bike frames, I find that a smaller tip is desired for doing just about any add-on bit, a larger one is for fork crowns, lugs, and bottom brackets. Keep that collection of tips! For racks with .028/.035 thinwall tubing I'm using tiny flames.