I assumed tig because you said Multi-Purpose. That usually means MMA/TIG/MIG
I think the M-Pro 252 would be ideal as its a true 250 amp output, as it will weld thin stuff with a 0.6 or 0.8mm wire and then for the thicker stuff you can still get into spray arc with a 1.0mm wire. You will need atleast a 16 amp supply though.
Why not use an arc welder for heavy stuff (up to the 10mm mentioned) and get a good quality MIG of 150-200A for thinner materials.
Well , my TIG has stick on it but my skill with it is not very good !! Can very good quality welds with good appearance be achieved with stick ?