It probably makes sense to mention the advantages of using an oxygen concentrator instead of bottled oxygen in some circumstances even though it might not apply to the OP’s question or needs. Oxygen concentrators are used in the medical industry to help patients breath when their lungs aren’t working properly. They take the nitrogen and carbon monoxide out of the air to supply 90%+ oxygen. In the States they are highly regulated for the medical industry but used ones can be sold for non-medical use. Lampworking (playing with molten glass) is the hobby where they are used the most. They can sometimes be found cheap at Goodwill or Craigslist even though they are expensive new. Of course the most likely source is from estate sales after someone dies. With luck they can be found for as low as $100. I bought a refurbished one from M&M Medical Repair in Beaverdale, PA for $300 that came with a 3 year warranty.
The most common ones have an output of 5 liters per minute (lpm). This is enough output for all Victor TEN torch tips but not enough for the bigger Meco Midget tips or a rosebud. That would require 2 operating in tandem. They have a knob that regulates the amount of oxygen flow. This takes the place of a regulator (since there is not a need to reduce the pressure in a tank). The obvious advantages are safety (no pressurized tank to explode or become an unguided missile), cost and convenience (no need to pay for refills or travel to get them). In bigger cities restrictions on transport (a welding supply store won’t let you put them in your car) or their delivery to non-comercial areas as well as housing and insurance regulations prevents in many circumstances pressurized tanks to be rented or refilled from a local welding supply store. BBQ tanks are the exception because they are popular and city authorities don’t want to be voted out of office for making unpopular rules.
I have found that different models vary quite a bit in output (even if they are all rated at 5 lpm). My DeVilbiss has a greater output than others and has a brass B size fitting that a welding hose can directly attach to. Many have just a barb that is designed for clear plastic hose to be shoved onto it. There are plastic converters with a barb on one end and a B fitting on the other that can convert the plastic hose to a welding rubber hose. A piece of plastic hose goes between the 2 barbs and the female end of the welding hose can attach to the male end of the plastic convertor.
A disadvantage of a concentrator is that it takes a couple of minutes to purge the lines until pure enough oxygen is coming out. It will blow out the flame if started too early. They also make some background noise.