Word of caution from me... Don't buy any welder online, buy one from your local Harbor Freight. I weld professionally and I run HF almost exclusively. They have the best guarantee and yes they are Chinese (Taiwanese) but if it fails for any reason, you can return it within one year for a replacement plus you can extend that warranty up to 3 years.
You buy ANY welder online, and it pukes, you are screwed. I actually have 3 HF units, I have their Pro-Tig TIG welder with an Everlast water cooler and a CK Worldwide water cooled torch and 2 HF Plasma cutters, the 65 Amp model I use on my CNC plasma table and the 45 amp model I use for general cutting in the shop and even the Pro-Tig and the plasma cutters will run on 110 volts (at reduced output), not that I do as we have 220-1 as well as 220-3 in the shop.
For me, their guarantee as well as their pricing mad me switch from Lincoln and Hyper Therm to HF and HF's plasma cutter consumables are light years cheaper than Hyper Therm. I got lucky and sold both my Lincoln Square Wave TIG and my Hyper Therm plasma cutter and I've never looked back.
The HF mid range MIG machines are all convertible to shielding gas btw.
As with tractors, always buy local with welding machines. In the long run, if they fail, you can at least return it and get a new one (How HF handles their warranty).... You buy online, you are basically hosed.
All the newer solid state welding machines are mostly made offshore today, even Lincoln has the bulk of it's components made offshore and same applies to Miller. They are all IGBT machines today. The old school transformer machines are for all intents and purposes, obsolete and the IGBT machines are much more efficient as well which is important when you are paying for electricity.