Everything labeled internally for a 240sx will fit your stanza. Pistons, rings, rods, crank, valves, guides, springs, flywheels etc, and as for cam shafts, get it re ground at a cam shop and SSS on here makes SOLID adjustible lifters.
As for intakes, you can get a custom one made up as an exhaust shop.
And as for aftermarket engine management, AEM, WOLF 3D and MEGASQUIRT all make a plug and play ecu for these cars.