I've been building up my 2000 Boxster S and have some left over parts.
Schnell Front Camber Plates - New, never installed.
Bought for $329. For Sale $299 + shipping
Brey Krause Side Mount Seat Adapters - Mounted once for a week and never used on the track (not low enough for me, so I had custom mounts fabricated)
R-9071 - Driver's side standard mount for factory manual sliders, fits 986 & 996
R-9074 - Passenger side GT mount for factory manual sliders, fits 986 & 996
Bought for $167 each. For Sale $150 each + shipping
Porsche GT3 Seat Sub Mount Bar - New, never installed in original packaging
Part no. 996-521-933-90
Bought for $55 each. For sale $47 each + shipping