A felllow Pelican, Ed Mitchell -aka - 'ivangene,' had the answer...His couplers and his 'secret shifters' were both excellent products that worked extremely well...Unfortunately, due to his wifes illness he quit making them.
http://forums.pelicanparts.com/porsche-911-technical-forum/779102-seine-gate-shifter-vs-secret-shfter.html#post7730616
Seine: $150
Secret Shifter: $250
Rennshift: $500-550