Mig welded my 3 door with %100 argon and it came out very nice. The two seat mounts had rotted through. Sprayed some gooey undercoat over the bare metal and that was it. Don't mig weld on the body with flux core. It looks like shite and splatters all over you.

Unless you are a good fabricator/welder, leave this to someone who knows what they are doing.

So yes, get it fixed. Pay right money for the right job.