[kbinkster]

Do you already have a twin line T-grade hose set? If so, you can use the green oxygen line with an oxygen cylinder.

A welding shop (or a glass supplier) will have the best selection of regulators. You want to buy based on function, not cost. If you buy a cheap regulator that fluctuates at low pressures, then you have wasted your money.

A C size cylinder typically holds 170 liters of oxygen. To give you an idea of how long that would last, if you are using 5 liters per minute, a tank that size would last you about 34 minutes. If you are using less, naturally, it will last longer, but that still isn't very long. A K tank is a pretty common sized tank used by beadmakers. Some of us have special cylinder dollies to help transport them. Some people roll the tanks on their ends to move them to where they need to be. They are very heavy, but mostly manageable unless you have physical limitations. You should always chain your tank to a wall. If the top valve is somehow knocked off, like from a fall, the cylinder - regardless of size - will become a missile, and is capable of going through cinderblock walls.

Hooking up to an oxygen tank is not terribly difficult, but you want to make sure that you do not cross-thread the regulator onto the threaded outlet on the tank and you want to make sure that there are no leaks. Do not use teflon tape. Always open and close the oxygen valve on the tank all the way - never partially. Back out the T on your regulator when you shut down. This will help your regulator last longer.

Using flashback arrestors is not a bad idea. It's an added safety feature. Some people advocate using them at the tank while others advocate using them at the torch. I'm sure you can find more information in the safety section.