Baja RS's are $$$. The only consideration with the Mastercrafts is they might be taller at the knee bolster then you might like. I know my Rubicon's are 1-2" taller there. This became a issue since my steering wheel doesn't adjust and to get into the driverseat, I had to 'drop-in'. I couldn't really get my thigh past the wheel. I'm not sure if the Baja's are that much different though.
For a rear seat, I'd get the matching Mastercraft seat. It's a better seat then the OEM's. It won't 'fold and tumble' though. Still any back seat is a bit tight for two adults for any extended period of time. For small kids, they are prefect though. Used OEM seats come up for sale once in a while BUT, you've got to make sure they come with brackets. Otherwise, you won't be able to install them and no one makes the brackets.