I'm an licensed electrician (now a project manager, not a field working electrician) and pretty much so everything Brian said is correct. If you go through the trouble of putting in larger power make sure you spring for a nice sub panel in the work area. It's so much easier to wire outlets, air compressors, blast cabinets, etc. with a sub panel. Most residential panels will limit you to a 100 amp or maybe 125 amp branch circuit breaker depending on the brand. . If you can install a 100 amp breaker in your house panel to feed a 100 amp panel in your garage you'll like that as your equipment grows. Most items are never running at the same time so it will run a lot of items in your garage without problem for a hobby fabricator. Also if it's in your budget install a couple of different 50 amp welder outlets of the same circuit to maximize versatility with little added cost. Again you will probably never have two welders running at the same time. Remember to make your 120 volt outlets GFCI for safety---it's worth the extra money for the safety factor.
Miller 210 MIG
Eagle 3-Cylinder Compressor
Air Tools
Body Tools, Shrinker, Stretcher
Bead Blast Cabinet
Homebuilt Car Rotisserie
1971 Dodge Challenger, Pro-Touring, 6.1 Hemi, Fikse Wheels, 335/275 Tires (in progress)