The Spyder, though similar to a Speedster front end, doesn't have the same amount of room as the Speedster. Especially with Greg's frame tubes.
I don't quite understand why the suspension pickup points couldn't be replicated in a Spyder, and simply use the A-arms and coilovers supplied by Mendeola. It appears the Mendeola uses VW spindles. The rack is rear steer, and might interfere with the tank. The existing VW is rear steer, and the rack conversions for beams stick with that. A 911 rack and double U-joint to the column could be used. But I think using the A-arms without the Mendeola mounting might be the way to go rather than fabricate the whole thing. It looks easy to locate sway bar bushings too.
The rear can be a rather simple 4 bar(two trailing links and two lateral links) with coilovers. I already have a design for a three bar(using the existing trailing arm with two lateral links), this was used in early Corvettes among others. I didn't invent anything, I just figured how to attach the lateral links to the existing frame and have them be strong enough.