I thought OP talat was very clear on the engine he is after - NA1 stated in thread title!
That along with 'manual' is probably as specific as you want to be if looking for a car such as the NSX, only ever available in small numbers at any given time.
I have read many posts on these forums where the poster is looking for a car and specifies their requirements in great detail - inevitability someone will quickly post saying 'you need to be less fussy if you want to stand any chance of finding a car'!!!
2001 3.2 Circuit Blue Coupe with pop-ups!
"If you want to argue that The Best Car in the World is a supercar, go ahead. But there is only one that makes the grade. Only one that's built properly.
Gordon Murray knows.
Rowan Atkinson knows.
It's the Honda NSX."
(J. Clarkson)