What buckets will fit in a 91 S-10?

[84GNTTYPE]

My brother has a 91 S-10 regular cab wants to put bucket seats in it? Does anyone know what will fit? I know Blazer seats of the same style will fit . . . but what else? Thanks.

 

[86BGN]

I had a 87 with Fiero buckets, kinda cool with the speakers in the headrest