Kev, how much welding has he done already? Enough to know that he will like it? By the time I grad. from H.S. I had done oxy/acetylene, brazing, and arc welding in shop class, and some of the guys were doing MIG and TIG and learning some cool stuff. I have done very little welding since, but I supervised trades and crafts guys, which included some top notch mechanics and welders. I don't know exactly how they got their start, but it was years ago, and probably would not apply to conditions now. I do know one came from the Navy (can't remember if he was Hull Technician or Damage Controlman rating), and the other was from WY so possibly the oil industry.
With respect to 2 semesters, welding is now so technical that 2 semesters will just scratch the surface. Hope he likes sitting in a classroom because there will be some math, metallurgy, physics, chemistry. I say this because I went to trade school before I went to college, and even back in the '70s we had those subjects taught to us. So like any education, it will be an investment in himself, and require a lot of sacrifice and $$. Hard to say what is the right choice. Some kids no doubt get their start at a local repair or mechanic shop, but to be really well-rounded, and at all competitive, I think a formal apprenticeship or military schools would be needed. Locally, the SSVEC or the generating station might have some opportunities - maybe Freeport - McMoran? Apache Powder? Southwest Gas? I would think getting into an apprenticeship with these companies would be very difficult, but some kids do succeed at it. Best of luck to him, sometimes getting from point A to point B is anything but a straight line.
With the global energy issues looming on the horizon, I think I would look at petro-chemical pipeline welding. That is a well-paid and stable field, at least it used to be, but they can pick and choose from pretty much any list of candidates.