It's been many years since I made a living welding. If I were going to set up a shop/business I think my tool/equiptment list would be something like this.
Generator / stick / mig combo
Torches
Plasma cutter
Air compressor
drill press
grinders
band saw
press
and on and on and on
Make your own work table
Buy or make your own trailer to haul the main tools to a job site.
I could day dream about
my new shop for hours at a time.
Used to build these trucks when we weren't out on a contract. Then take them out to the job site and work away. Ah, the good ole days.
Good luck. Hope you do good.