Hey i bought a mig from a workmate, its a 120amg gas/gasless welder, but I want to use it with gas. Where do i get a bottle from? i know Boc Gases make them, but do i need to get in contact with them, or buy it through a reseller? Also is 120amp strong enough for work other than panels? I mostly bought it for rust repair, but would like to do a bit of fabrication too, such as seat rails and rollcages, etc.