Good god, the amount of hand wringing and fussing over the paint on a cylinder is absolutely WILD here. I can't tell sometimes if it's just trolling or an honest to god mental issue, but I've never seen anything like it anywhere else. Insisting on keeping perfect paint on "your" cylinder will only serve to aggravate the welding supply and cause you nothing but issues. This entire industry is built around the idea of exchanging cylinders so it's easier to maintain cylinder integrity (testing and safety becomes the burden of the LWS instead of the customer) and being able to bulk fill cylinders to be efficient and therefore cheaper. Being a thorn in the side of the supply house will do you no favors. I have owned a welding and fabrication business for many years and dealt with welding gases of all kinds, it behooves you to play the game by the rules the supplier has set down.
OP, go to your LWS (local welding supply) and ask them what the largest cylinder they'll sell you outright is. Buy that one. The bigger your cylinder, the cheaper the gas is per cubic foot. Get 75% co2 25% argon (also called C25) and a spool of .023" or .030" Lincoln Superarc wire. Don't lease a cylinder. Don't buy one from the farm store or amazon or wherever. When you run out of gas, you just swap it out at the LWS and you pay for the gas. Buying from the LWS is about the only way to ensure you won't get the run around when you need to exchange the cylinder. Welding cylinders are expensive because they are extremely dangerous if not made correctly and not maintained, and there's a tremendous cost associated with making and distributing pressure vessels. The good news is they maintain their value pretty well so if you needed to sell them later you can recoup most of your cost.
If they allow you to, set up a charge account with the LWS, even if you just pay at the counter. This usually gets you better pricing, account history, the ability to look up past orders or parts, and usually gets a sales rep attached to your account who you can call with questions or if you need to buy something. The difference in price can be staggering. What costs a joe public customer $150+ costs me $35. Strictly because I have an account. I set up my charge account long before I had a business and I was just working in my garage at home. I had gas and supplies delivered by a sales rep when I was 19 years old welding on my uncles truck at his house.
Good luck.
and also what a adequate size tank. The welder will be on a single welder, roll around cart.
