I definitely recommend sports package.
As mentioned in previous posts, don't let the dealer force you to 'settle' on something. I got a 2011 new last March. My requirements were MT + Sports pkg. My local dealer found what I wanted in Oklahoma and had it shipped down to Austin. It's just not a big deal even if they try to make it sound like it is.
*EDIT*
BONUS: if you're 25 or older and close the sale before they have the car on their lot, most dealerships will give you a loaner Z.
It was so awesome to have some real fun before getting my own new Z which needed a full break-in.