Hey 1989.

That's a good looking car (for a Chebby)

Off hand I don't know of any for sure, but I think you might be able to get a set of Late 80's-early90's Mustang GT seats in there. I've used them before in some pretty tight spaces.

They are light and comfortable, give you fold forward and recline, and pretty affordable in the junk yards now adays. LX seats of course would work, but aren't quite as comfortable.