I'd just wait for a 3 door set if I were you.
They won't slide forward far enough to get people in the back without having to wind the seat forward on the wheel and then it will still be tight as they don't collapse forward like they do on a 3 door set. You also need to think about people getting out the back if you have an accident. It's worth waiting and doing the job properly if you're putting the effort in to swap them in the fist place.
A 3 door set in a 5 door would be OK, though having the lever on the top corner of the seats would still annoy me as I'd know it wasn't supposed to be there.
Cheers
Stu