Why not get both? Both are different cars anyways. I own a G35 and it's NOT the best handling car, comparing to S2K. But response VERY WELL to suspension mods.

S2000 is straight out the box OEM handle better than the OEM G35.

That being said, I'd prefer the 350z as a DD instead of the S2K. Gotta love that torque. Z&G parts are interchangeable and the Z handles quite good, being stock.