Michael:
From your description, it appears that you are talking about silver brazing, (sometimes called silver "soldering"). Just go to any welding supply and ask, and they will sell you a coil of the expensive stuff, and the appropriate flux for what you want to do. Follow the instructions on the flux, and in general, the same procedures as in regular brazing, and you should be o.k. You will also need a small tip and lower heat settings on your OA outfit.
Welcome and good luck!