If you put Oxy acetylene near that arch you'll ripple the panel. The other areas would be fine with it. Even tig can ripple a panel with the heat build up. Buy a mig welder do it yourself it's really not hard the secret is to weld pause weld pause to the same timing as you say those words. Do this for no more than an inch at a time then allow it to cool completely( never quench it or blow compressed air on it). The metal must be super clean both sides with a 1 mm gap on all sides of your ( butt welded) patch , buy argoshield or even better argoshield light not co2. Practice on some sacrificial metal before you go near the car. Like most things in life the key is in the preparation.