I use a Little Torch with oxy propane.
I use the 1 pound disposable propane bottles. Unless you do a
tremendous amount of soldering, a one pound disposable bottle will
last you a very long time. One pound bottles are available at most
hardware stores and cost about $4.00. Please do not use a 20 pound
propane bottle from a BBQ in your home. It is not safe.
For oxygen, I use a larger bottle (can't remember the size right
now) of oxygen, compressed to 2000 psi. These are available at
welding shops. You can rent or buy them. I bought mine for $185. A
refill costs about $30. I would not use the disposable oxygen
bottles. These bottles are about the same size as the one pound
propane bottle, cost about $10 but contain very little oxygen. I
learned the hard way. I would use up two of these in one day of
soldering. On the other hand, the compressed oxygen tank lasts me
about a year.