You can make a prettier weld with the TIG but it takes a lot of skill/practice on aluminum.
MIG will be at least 10 times faster, still requires a decent level of skill. You should use a spool gun for the MIG.
Aluminum must be prepped properly and if doing starts and stops while welding it needs cleaned between. Make sure your scratch brush is stainless.
Key words are production, unless you are making a fortune on these or they are highly cosmetic MIG is the right way. If they are highly cosmetic better find yourself a welder with a lot of years practice on aluminum.