OG racing sells them but, their prices aren't that great. I'd try to find some local place so you can go back and ask questions.

Strato's 100% right about the modifications, my sparco Evo bolted right up but, the Evo-L required come drilling. I have the larger seat on the passenger side because there's no telling how large the instructor's going to be.

I ended up using the drivers side without sliders because I wanted to be as low as possible. That might not be possible on the S2K because you have to access the mount bolts.

Of course sparco's going to deny any knowledge of other companies seats.