You can use 2000 to 2003 or 2004 whenever the qx4's last production year was. Unfortunately, you cant use pathfinder doors even though they will fit fine for 2 reasons.
Refer to the picture below:
Reason 1 (RED ARROW), The pathfinder does not have the body panel down here pushed out like the qx4 does, so if you replace one door with a pathfinder one, and the other is a qx4 one, it will start looking like a 1990 honda civic with mismatched doors, and different colors everywhere, you get the idea.
Reason 2 (GREEN ARROW), Again the qx4 has enlarged fender flares, alot bigger than the pathfinders, which as you can see, the rear door is molded into the fender flare, which pathfinder doors are not, plus pathfinder doors also do not have the pushed out body panel as in reason 1.
All parts are mostly interchangable between a path and a qx4, except i think the only things that really arent, is the body panels. I mean they will bolt up fine, but for car appearance purposes, like i said it will start looking a honda civic with mismatched everything.
Hope this answers your question, so unfortunately your now limited to finding a qx4 instead of both cars.