....Anyway - given the different processes of welding, which one did your son excel in? We have to face the fact that MiG welding is largely doddle to master in workshop environments, whereas Arc/MMA welding is a different kettle of fish, and needs a good steady grip and control, etc (bit like having fun with yer missus, in principal!:lol ); oxy-acetylene gas welding is a bit dicier, given the naked flame & fuels volatility (and gas welding buckles the bodywork like mad, anyway) - although TiG welding is the business on thin (Jap) bodywork, as it's low temp'/low distortion, but takes as much skill and dexterity as gas welding.
Gas welding kits are hard to buy & get bottles for due to licencing and insurance restrictions, arc welding kits are cheap and plentiful (but will blow-away any bodywork, as the lowest they'll go is usually 40amp); MiG welders are only a little more expensive, but again, for car bodywork, you need low-amp flexibility or risk the blow-away problem as in arc-welding, so 140 or more amps is great for chassis', etc, but if it won't go down as low as, say, 25amp with 0.6mm wire, you'll struggle (unless you can clamp a copper block behind the piece you're welding, to take away the heat).
The choice, as the old saying goes, "makeitfit", is all yours! No doubt you'll both have fun & games with whatever kit you get..or end up with a vehicle full of "burnworm" holes!
:lol