I have made some repairs on restauraunt equipment and have all been small. Both aluminum and stainless. I used the TIG every time, the pieces I had to repair were small and a spool gun on the aluminum would have been too big, probably not impossible but would not have looked as nice. The racks and trays usually have cracked welds which can be easily tig'd up. Most of the time with little or no prep. Most equipment is pretty clean [no paint and little oxidation]. Although the Mig is easier to learn the small repairs would be better handled with TIG, or....just buy em both