Are you looking for someone to do the work or do you just need access to a welder? I've got a 120v Hobart wirefeed you can use but as a rule, I don't do welding for people I don't know that well (liability). Given how long it's been since I've done any serious welding, you likely don't want me splattering booger welds all over your Jeep anyways.

I've pushed it to 1/4" for non-structural and 3/16" for something that needed strength. It did the Ford 8.8" and fullsize D44 swap on my old CJ-7 without any trouble. Are you just adding some light tabs to the rack or something?