Mig or Tig welder?? - MIG Welding Forum

Hi all, this is my first post, but Ive been lurking around this forum for a while now.

Im new to welding having only ever played around with my old stick welder, but one of the guys at work is offering to teach me to weld both mig and tig so that I can help out more with the engineering side of things.

Anyways!
At home for my own leasure and for practice I want to start making myself some weight training equipment but can not decide what type of welder would be best for the job.. MIG or TIG? In time I will own both as they will be used at work but for now I can only afford one.

here is the sort of thing Im looking to build

What would you recomend?

Thanks
Dave