I'll assume you're talking Scout II. The only seats that I've heard of that are a direct fit on the factory bases, without ANY modifications or fabrication to the bases, are seats from a late model (approx '94) Camaro. That's if you're on something of a budget like me.
If you've got money to burn, or want some real trick seats for off roading, then you might want to consider Corbeau buckets. They make some that fit right onto the Scout bases without any mods, and if I remember correctly they also sell replacement seat bases for Scout II. Some of theirs have slots in them for four point harnesses and such. But like I said, expensive. If you're interested, go to their website at www.corbeau.com