Not sure if you can fit 16" BBS RS centers (off a 928 for example) and 18" step-up/slant lips from the the likes of VR Motoring, Spinfab, Memoryfab or RB wheels. These might not clear the brakes of the 996 like they do on the 964.
Someone mentioned OZ Futura, how about these http://www.ebay.de/i...=item462c60fd73
Or better yet, some E28 or E88
I have these 9,5/10,5 in the basement, but no Porsche