Being someone who use to weld for a living our machines could run all day and night and some times they did.

In your case you shouldn't have to worry to much about that, but what about when you decide to weld on a frame? And something also to think about is a availability of being able to just plug in to a 110 receptical, my mig welder is a 175 and it a singal phase 230 volts, so not as easy to hook up in a friends garage.