Tig welder for a beginner

In my opinion, TIG welding requires a significant amount of practice to do a decent job. I had used a stick welder, and oxy /acetylene for 10 years before I bought a MIG. It was dead easy to use and get great welds. Then, I decided I wanted a TIG to weld my roll cage and other things including aluminum.
I bought a Miller TIG machine, and until I had about 40 hours of practice under my belt, I couldn't weld anything worth ****, even with my previous gas welding skills. TIG requires MUCH greater skill and has a lot more variables to deal with than the MIG process. Tungsten types and sharpening, pedal control of the heat, not dipping the tungsten... there is a lot to learn. Learning aluminum on the TIG was another whole process.
Unless you are really interested in learning the TIG process, and are willing to spend the practice time behind the torch, I would suggest you consider looking into a spool gun for your MIG welder instead. The learning curve there is much lower, the investment is much smaller, and you can fix your pontoon boat as good or better than the factory built it.
Just one weldors opinion...