AHAHAHAHAh o buddy you have come to the wrong place. There are so many people here that know what they are talking about, that i can count them using my fingers only...maybe couple toes.
Not to say that at my350z.com everyone knows what they are talking about but advice from them will be based on personal expirience with the Z. Not F&F.

And you do have to give out more info then that, nobody knows what type of end effect you want to achieve nor what you have to work with as far as money goes.

If you have money do Plenum spacer, ypipe, DC sports headers. Those will yield noticeable gains.