Dont rush into it. Just use your eyes and your contacts and see what you can find. There are some really good deals to be made, but you have to wait and look for them. Finding a mast and a boom is a priority, then begin looking for other fittings and foils/ruddersystem etc. But before you do anything, consider how much money you can spend on this! There will be some cash spent on this..
About crossbeams, you wrote:
Teardrop shaped 5" X 3", wall thickness is approximently .080".
I think that will do, but Phill, Wouter and others are more qualified to confirm that. Unless you can source carbon at industrial cost price, carbon will probably be more expensive. Finding 90mm diam alu tubes with 1.6mm wallthickness at a good price should be possible.
Parts is something you always can sell again, so you minimize your risk by beginning in that end if you are to do a boat on the cheap. The hulls are a relatively well known quantity.
