If you want to use Paulownia for any of it, I will have a heaps of different shapes, sizes and thicknesses very shortly including bead and cove for the rails.
If you are keen let me know and Ill get some more info to you.
I’m in Melbourne and I’ve hacked out two basic HWS’s so far. The first was sort of a “Jensen” style construction using pretty common materials and hardly any power tools. I used 7mm exterior ply for the spine and ribs and 4mm Hoop Pine marine ply for the deck and bottom skins. Polyurethane glue is what I used on this one - it “foams” slightly to fill gaps and is readily available at most hardware stores. I constructed the rails from pine strips rather than the solid cork and bending ply. Paulownia is easily available now though, so there are heaps more options. I glassed only the outside of the board with 4oz top and bottom. Build photos can be seen here if it’s a help.