would it be hard/possible to swap racing seats from an 89 crx into a 00 civic coupe and swap the civic seats into the crx??

 

Sure, just change the seat pans.

 

just to clarify for the OP, this is for swapping the ones from the civic to the crx.

The racing seats should just need new universal rails... buy the ones made for a 96-00 Civic and compatible with your racing seats.