+1 on the big down payment and financing it. Just be sure not to pay it off to quickly as that can actually hurt your credit. They usually have a time period that you can do the complete pay off after a certain point and it won't count against you. I know it sounds counter intuative, but they want you to pay them some intrest for a while, even if it is only .99%, so it makes it worth their while to loan you the money. Just be sure and ask your dealer about early pay off penalties, and how long you should wait before you should pay it off completely if that is your plan.
But yes, get the 1098, and don't wait till '09. "IF" the 1198 does come out it will cost a lot more, and the 1098 is already an pretty vicious animal as it is. You won't be sorry. (An 1198 would be fun though )
-ND