You could just take the old parts out and drive with it for a while to see how it feels before springing for the $$$ on the new parts. You will just have a few metal looking brackets exposed and possibly the integrated telephone terminal exposed.
Do just steps A and B from this and then test it
From this article (which you have probably already seen
)
Porsche Boxster GT3 Center Console Upgrade - 986 / 987 (1997-08) - Pelican Parts Technical Article-