Just my opinion, based on my own experiences - I would go with any Lincoln or Miller hands down over ESAB or any other brand. I've welded more pipe in refineries with Lincolns & Millers than any other brand. I would especially go with the Lincoln 210 MP if I were in the market right now. A 210 amp multi-process welder at that price is a good value. The thickness on MIG is 5/16 which is a bit light, but if you bevel your weldment correctly and run multiple passes it will be just fine, and give you a better finished product since your not dealing with crazy high heat/distortion. As a comparison, I have a Lincoln Invertec V350 Pro that I run a Miller Super SP-32 wire box with. Regardless of what I'm welding, I stay right around 25 Volts, which is roughly 190 amps, and that machine is capable of up to 34 Volts/350 Amps. Welding is a lot like painting, it's 95% prep work and alot of passes!
The majority of my welding career revolved around these parameters:
Heli-Arc: 80-160 amps
Stick: 80-140 amps
MIG: 25 +/- Volts
Those numbers are what I'm basing my opinion of the Lincoln 210 MP on. I could literally have used that welder to make a living with, welding Sch. 10 to XX Heavy Wall material. Hopefully I helped you out, I'm sure that whatever you go with will be good!