1998 SLK-230 or 2001 SLK-320?

Hi I am 16 and looking to buy either a 1998 SLK-230 or a 2001 SLK-320 within the next year. I have read many great reviews about these cars, they are both beautiful and within my price range. Please don't tell me not to buy a benz because of the costs, I work a steady $15/hr job 20 hours a week. My main interest is the maintenance costs associated with these vehicles. Either one will have around 100k miles on it when i buy it used with NO warranty. I was wondering if i could buy a warranty for the car from somewhere?

If i need any other info, I will make sure to update the post, Thanks!

slk 320, would not waste time with the 230.