If you're willing to spend up to $600 on a welder, I would recommend something like a Hobart Handler 140 if you don't have a 230V outlet in your garage.
I did my entire car with my Eastwood Mig135, and a bottle of gas I bought from Cyberweld. It's a 120V welder and had plenty of juice for welding up frame rails and subframes and some of the smaller projects i've used it for. I've done 1/8" structural tubing and didn't even had to crank the power up as far.
I now wired in a 220-240v outlet in my garage, so if i could go back, I would be more inclined to buy a 220V machine. But I think i paid under $400 for the Eastwood (they have occasional), and $200ish for a tank of gas shipped to me (was during covid, none of the local welding shops would sell to non-commercial accounts), and maybe $100-150 in equipment line a card ($50 harbor freight, a self-dimming helmet of Amazon and some clamps/wire brushes and wire.
I have used Flux with it, but I get much nicer welds when i used gas.