No credit card will provide guaranteed upgrades on any airline. Two Skymiles credit cards issued by American Express will give you a number of EQM (Elite Qualifying Miles) which will allow you to qualify faster for the next level of Skymiles elite status. Read about the Platinum and Reserve cards here:

http://skymilesoffers.delta.com/cred...umer_index.php


The other possibility is an American Express Centurion card, but it exceeds your stated budget and you cannot apply, you must be invited. It is generally believed that the minimum spend to elicit an invitation is between $250,000 - $500,000 per year. Centurion includes automatic Delta and US Airways Platinum status, and other benefits. There is a $5,000 initiation fee, and the annual fee is $2,500.