Why not both? Not gonna be cheap to get a reputable multi-process unit though, Lincoln have some compact ones starting at around £1200, Millers are another £500 on top of that.
Also an option. I have both. 2 TIG, 1 MIG. But for the price of a single unit that can do both, you can get two separate units and have change left over.
Why not both? Not gonna be cheap to get a reputable multi-process unit though, Lincoln have some compact ones starting at around £1200, Millers are another £500 on top of that.