Don't waste your cash on the tweeko stuff. American torch tip in Florida sells to everyone. Call them and get a gun with a spare liner "90% of feed problems are from kinked liners". Pick up a couple bags of spare contact tips to learn with. I'd run .030 wire and a trimix from your local gas supplier. You don't want to do flux core welding on a car. Flux core is designed for field welding where the gas would glow away. Even a professional welder has difficulty making a flux core weld look great. Tig welding is great but it's almost as slow as brazing, and much more expensive. It's a real art to do nice welds with one, but its a very slow process.
I'd get either a new miller 110v, or the Lincoln 110v. They are both good machines, just shop around. They sell the regulator with them. Don't forget WELDING gloves, and a power welding hood. Cyber weld has everything at the best prices I've seen. Get your consumables from American torch tip.