Are there seats from other vehicles that will bolt into a '93 Mazda B2600i 4x4?

Since the B series trucks are essentially a rebadged Ford Ranger (with a few other minor differences,) a Ranger bench or buckets should fit w/o issue. As far as any other seat from another vehicle being a direct bolt-in, you would have to take some measurements to be sure... but that's Hot rodding!!

yep what richard says. i had a nissan 720 truck and the guy that i bought it from put electric seats from a mustang in it. but pretty much put any seat in you want just make sure you use grade 8 bolts and that they are not bolted into just sheet metal aka floor panel