Which Boxster S would be a better purchase in the long run?

[hamburglar]

I'm looking to buy a Porsche Boxster S. Right now, I've found a dealer selling a 2000 with 104,000 miles on it for $11,000 and a private seller with a 2003 with 40,000 miles for $17,000. Now I like the color of the 2003 and the fact that it is newer and looks to be in great shape, but it is significantly more expensive. But what I'm concerned about is major costs down the road. It seems much more likely that I will run into something like a timing belt replacement on the 2000 one due to the higher miles, and that would be a significant cost. Would it be better in the long run to buy the newer one with less miles? Or is 104,000 miles okay, given that it is much cheaper? I don't want to buy the older one and have to do a $4000 repair a year from now if the 2003 one won't give me that problem. Obviously there's still a chance that one would need a major repair, and a $4000 repair after spending $11,000 is easier to handle than after having spent $17,000.