Ian c, not much help there. It's the best shop in town; I want to do it myself! Gforrest, thanks for understanding and trying to help, but I was asking specifically about the points from the Pelican Parts 101 Boxster Projects book (and their Technical Articles on the web). Deserion, hmm, that might work, although I'm not quite sure what "rear crossmember" you mean, or where to place the 2X8s.
Anyone else

?