looking at purchasing a new mig welder with about £400/500 budget and after advice. Will be doing mostly car body and chassis work with some additional fabrication work with max 4mm metal. Have a sealey No gas/gas mightmig 150 that have set up with a full size hobbyweld gas bottle. Now would like to go to the next level. Is this possible with budget or do I need to stretch a bit further? Any advice on mig welder in that price range?