I'll be watching intently. My dad just bought a big blue for his Goldwing, so I can get an up-close look at it when I'm over there, or ask for info. I've been wanting to do this for awhile, but just haven't wanted to pull the trigger on parts. I know the jack screw and bearing/nut for it are, for me at least, going to be the most expensive parts and I just scored several large scissor jacks used for leveling enclosed trailers.
What length is the main screw shaft you're using? Nice welds BTW.