You didn't ask for a product review, but ... in the past year I purchased this unit:
https://www.amazon.com/gp/product/B0B1TGZ8XN/ - no affiliation with the company other than a very satisfied customer. This is advertised as a "6-in-1" unit, meaning it can do SMAW (stick), TIG, and four variations of wire-fed welding: MIG (gas), flux-core, "spot-weld" (ability to set a timer to get a consistent, brief tack), and spool gun. It is dual-voltage, so able to run on 120V or 240V (adapter included). It comes with a regulator for the gas, as well as different sizes of drive rollers, a spare liner and nozzle, and a few contact tips; it also includes a basic SMAW electrode holder. It does not come with a TIG torch, nor with a spool gun; those are extra cost.
Note that there are any number of inexpensive, import, multi-process welders out there which combine at least the first four modes above - SMAW, TIG, MIG, and flux-core. When I was looking, there seemed to be two distinct levels of machines, both of which claim anywhere from 160 - 250 amp output (the higher-end claims are, of course, overly optimistic). Pretty much all of these have a "synergy" mode, where you set the output in terms of amperage, and it automatically calculates the wire feed and voltage. All (?) of these units allow some fine-tuning of the synergy settings for MIG/flux-core, but many (most?) do so so only with an arbitrary +/- setting - no way to tell exactly how much adjustment is being made, and whether the adjustment is to voltage or wire speed or both.
A couple of years ago I bought one of the lower-level units as my first MIG machine - Up to now (25 years or so) I've welded only using stick or TIG. That little unit worked okay for basic MIG and flux-core; it also welded stick fine within its capabilities; I did not try it with TIG, because for any of these machines, you really need a TIG torch with separate gas control - import versions of which are available inexpensively, but since I already have a pretty good TIG machine, not something I needed. Despite its limitations, it convinced me that I did want to incorporate MIG into my welding capabilities. Thus, when I took on a major project for a friend (major for me, at least - completely refurbishing and adding onto a 4 x 8 trailer), I took advantage of the excuse to step up to the "next level," resulting in buying the unit linked above. The primary reasons for stepping up included 1) higher output (still not sure it can really do 200 amps, but it certainly gets a lot closer than the first low-end unit I bought), and 2) ability to switch to full-manual mode, allowing more precise fine-tuning of the synergy settings (i.e., ability to adjust specific wire-feed and voltage settings).
Pros of this unit:
* welds very smoothly in MIG, flux-core, and SMAW, all on steel; haven't tried it on TIG or spool gun.
* dual voltage - I mostly use 240V, but have needed to run it on 120V a few times, and it worked well (only tried this on MIG thus far)
* Generally easy to use interface, with clear readouts
* has memory to store up to 10 sets of settings, allowing one to fine-tune for a specific type of project and save the settings for future re-use.
* Ability to switch from "synergy" mode to full manual mode, allowing full control and fine-tuning of settings
* "spot weld" mode is surprisingly useful
* fan runs only on-demand; shuts off when it is not needed
Cons of this unit:
* The wire-feed setting is shown in meters/second rather than in inches/minute - the latter is the way I nearly always see it expressed, but that may be due to being in the USA. The conversion is not difficult - the setting in meters/second * 40 ≈ the setting in inches/minute.
* the plastic strain-relief where the wire-feed gun plugs into the unit is a bit flimsy
As always, there are multiple brands that look more-or-less identical. When I bought this unit, I saw some others that looked like they had the same interface, but cost 10-20% less. Might those units work just as well? I have no idea. I went with this one on the basis of a few YouTube reviews of the brand. Again, no affiliation, but I have been very, very satisfied with it, and would not hesitate to buy it again.