Lol, not everyone can afford a GTR or willing to spend their life savings on a GTR lol.
Back on the topic, I'm pretty sure that any of the aftermarket seats that you buy will need rails.
Rails can be expensive, but if you are lucky, you can pick them up 2nd hand for $100-150 ea.
As for seats, I've got a Bride style one in my car, pretty comfy and huggy, no complaints, bought it for $300 brand new lol and got given rails by a mate.