Excuse my ignorance. If I wanted to upgrade my suspension to that of the sport package, what parts would I need to purchase? I am not familiar with the different parts that make up the suspension (Springs, shocks, etc.). Any difference between the sport package suspension and the Z suspension?

If you want to do a full swap you'll need 4 Struts and 4 Springs. I have the stock sport struts with the revised Zsprings and love it, its the way the sport suspension should have come from the factory. If you want you can just swap out your stock for a full 350z suspension. The 350Z springs will also lower your sedan 1" on all 4 corners.

Here's a pic back when i had the stock sedan sport 18's on for reference.

-GP-

Too bad there isn't a sedan sticky for this.

I liked the handeling on the 04.5 loaner i recently drove. It had the sports package. I heard that the Z suspension might be a bit too harsh.

Any idea where to get the sport package struts and springs?

IMO the Zsprings have the same ride quality as my stock sport springs, they just handle better because of the lower center of gravity and the car feels more together. You could prolly find an 05 sport sedan suspension in the classifieds.
-GP-

check in the tech forum under brakes and suspension- see sticky at top