I have a 4-way adjustable front passenger seat in my 2011 EX35 Journey. Can I swap it with an 8-way seat? Since all the motors and actuators are part of the seat itself, will the new seat have an identical plug?

Man that's one of those questions I've pondered while bored on long road trips many times.
Nissan is about 50/50 on commonizing wiring for stuff like that. Your best bet would probably be to check out the factory service manual and see if they illustrate it or talk about it anywhere.
Please post back with whatever you find though, cos this question burns my soul honestly haha.
https://www.nicoclub.com/infiniti-service-manuals

no, i dont think any of them come with 8 way on the passenger side, Your only sure shot way of doing this is shipping in a right hand drive driver's seat from overseas.

no, i dont think any of them come with 8 way on the passenger side, Your only sure shot way of doing this is shipping in a right hand drive driver's seat from overseas.