your best bet it to check in the junkyards. I know it is harder since the 93's have the automatic seat-belts. I was/am selling a set of grey leather seats out of a 94 SE.
They did have stock leather for your car though, so it's out there...only thing is the rear seat back and/or driver door panel will possibly have some damage. Those are nototious flaws in the older altimas stock leather seats