Hey-Hey!!!,
I usually play with tube designs supported and hybridized with some SS components. I have a small amp on paper. Push-pull, non-complementary, all cascode, all MOSFET and remarkably simple in its execution. It takes a tube-style/tube ratio output transformer.It might be best to try it on a headphone amp first...just to keep heat and high voltage under traditional welder limits. It would be easy and safe to smoak test...a resistor of 50R on a 4R car full-range.
cheers,
Douglas