matthew,
i think i remember hearing from a few board members that the e36 seats and those of that era were a little too tall for the coupe. Could be wrong here. And i'm sure that if you REALLY wanted to you could make anything work... just depends on how badly you want them in your car. I did a swap to e21 seats (e24 rear) last year and the procedure was fairly simple. The seats were manual, so there was no issue with locating controls or having room for them. I know e24 and probably 28 seats will fit - still have my eyes open for a nice set of e24 fronts.