I researched EXTENSIVLY into getting an audi before my Z. 99.5 is the lowest year you want to go with to have the clear projector headlights w/ the option of getting the HID kit if that is any importance to you. I wouldn't settle for the 2.8 as they are more expensive from what I have seen. Go w/ the 1.8T, intake and GIAC chip and put yourself up to 205hp. ( I know you have your Z for power but...) The 1.8T will definately feel more nimble to you. Even a 99 year will have the older reflector housing headlights. I LOVE AUDI'S... Good luck.
"Be kind, for everyone you meet is fighting a harder battle" ~ Plato