Ok... looks like we are talking 95 here. I've had and worked on many 95'*. First off..(joking here) discount anything performance the Venom said..he'* so old and and out of the loop that I'm surprised he didn't go lookin for a carb on his GXP. hehehe
Seriously though, the Bonne lacks aftermarket, the S1 Bonne is further lacking. Reason behind this is there were very few SC'd GM'* that caught the performance market before 97. In 97 both the Regal and Grand Prix got the S2 SC motor and it picked up by the aftermarket folks after that.
Folks have found rockers, smaller pullies and Sinister Performance for programming the pcm on the S1. Other than that there is little. Upgraded trans parts and shift kits are available through Transgo. For the most part though the trans suffers from fluid starvation at high rpms and the diff is a weakpoint that frequently comes through the casing when you abuse the car.
To date the fastest S1 without nitrous is running a 14.2 and having lots of dependability issues last I heard.
Others have develeped one off cams etc, but that is competely custom.
00 Regal GS: All kinds of cool stuff.