ZJ seats in an XJ

I'm trying to decide on new seats for my '94 XJ. It seems there's lots of later model ZJ seats available and I know they don't fit the frames of the XJ. I was wondering if anyone has swapped out their XJ seats for ZJ's? And if so, how difficult is it and what is involved. The other consideration was having my seats reupholstered and had estimates of around $450. ZJ seats are cheaper but may have to spend extra money for fabrication. Any info would be helpful.