Everything you have mentioned says mig not tig. In my opinion if you want to do general repairs on farm equipment & also railing type work you need to use mig. I would look into an engine drive & a feeder before a Dynasty. Tig has it's place but is to slow for general work. Stick has it's place but also is slow. I run my feeder 90% of the time doing mobile work. The other 10% is stick. I can count on one hand the times I've been asked to tig mobile. Sure some guys do a lot of it but not around a farm or construction site.