Hi Roy and welcome aboard.
Much as I love the old racing Porsches, Gary's own take on the Spyder just blew me away.
Before going down the 550 route, bear in mind a Vitesse comes with around 100bhp as standard and mine cost me virtually nothing once I'd sold off all the unwanted panels.
Work out how much you'd need to spend to get that sort of power out of a bug engine and you've pretty much got the budget for a finished Sammio Spyder.
Good luck whichever model you choose.