If you were able to ocate a metal coupe you were planning on fitting it to a tube frame and having the panels flip up as they do on your Speedster.
Well . . . here you go:
http://cgi.ebay.com/ebaymotors/1959-Porsche-356-A-Coupe-For-Parts_W0QQcmdZViewItemQQcategoryZ39405QQihZ009QQitemZ190146619854QQrdZ1QQsspagenameZWDVW
And the cutting has already been done for you.