Well if your buying new and don't want to spend an arm and a leg on a pulsed senergic set I don't think you will go far wrong with the esab warrior 400/500 amp sets. These are real work horses site machines. and are also classed as multi process machines. Mma, lift TIG.
We ran Esab/Murex 350A machines at my last place and they ran 24 hours/6 days a week in a production environment.
The only problems I had, apart from damage by incompetent operators was 3 fan and 1 PCB failures on 15 machines over 5 years, so they're pretty good IMO.