Inauguration Lenses

I'm planning to head down to Obama's Inauguration in January, and need to get some serious telephoto if I have any hope of getting a shot of him. I'm not expecting to get anything great from the distances I'll probably have to watch from, but I'd like nothing more to have my own picture of him at inauguration.

Here's my question, I want to know a) What's the most telephoto I can get for around $1,300 be it in a single lens or lens+teleconverter, and b) If I were to rent instead, what would you recommend? Also, I'd love to hear any other thoughts you have on shooting at the inauguration.