180 is a size that will do a lot of things in the mid range, but if you want to do really light stuff (body work) you need to have feed rolls for 0.023 wire and a machine you can fine tune at very low power settings. The 180T is fixed adjustment steps, you need a 180C to be continuously variable. Also, that size is reaching a bit once you want high duty cycles on 1/4" and up. Also, everything so far in this thread seem to be inverter welders, so totally dependent upon board availability in the future - ESPECIALLY if you want a "forever" machine. IMHO two directions to go: a slightly older, used transformer/rectifier machine - still brand name though - OR - consider the modern inverter machines as life limited. You can then go with a higher performance machine with a decent reputation from a discount supplier fully realizing that they can be replaced in the future when there might be another step up in performance. Another thing to think about: the US is getting so tired of China dumping into its marketplace with products that do not suffer the costs of being made to Western standards for materials, supply chain, labour, benefits, etc. you can expect the playing field to be levelled by tariffs - so support for offshore stuff could get as expensive as onshore (and even THAT is threatened as we have surrendered most electronic markets to Asia without a fight).
Of course, in best of GJ tradition I must tell you how many welders it takes for my home shop to cover full range. M 211 for portability and light gauge steel, L200 rect/xfrmr for medium duty steel fab, M250 AC/DC for medium Al tig, M255 for Al mig and med duty DC tig, M XMT 450 CC/CV for heavy steel fab (not using now - for bigger shop when it is up). I still need a water cooled AC tig system for heavy Alum and much larger plasma and table - but also need bigger shop for the table. Not suggesting you should fall off of the wagon and do anything as silly as what I do, but before you jump at anything take a long look at what is out there and think hard about what you want to do. If you want multiprocess - and there are a lot of those machines out there - they can be spendy but the alternative is to have a half dozen machines to do not much more of the same things.