The Europa hubs are the same as the 2 seat Elan front hubs with bolt on wheels, all Herald/early Spitfire. The knock on hubs are larger bearings & stub axle, same as the +2 Elan and GT6. I'm not sure how that'll help you though, I suspect what you have will either be custom or Ford stuff.
I would assume from the comments on the Spyder page that the upper and lower ball joints will be the same as the Europa top joints, usual Triumph Herald,etc.
Looking back through the thread, it now strikes me that the guy has bought a Spyder chassis and started to buy their running gear before losing interest or too much cash, and given up. I'd agree that basic engineering stuff (bearings, TRE, etc) will be cheaper elsewhere, but the easiest way of getting it mobile will be to talk with Spyder and pay up with a smile for their bespoke parts.
Brian
ps Incidentally I have Spyder front wishbones & bottom links on my car, they've been there for years and even now still look very solid.