Daisy-chain non-display port displays
Unfortunately, it is not possible to daisy chain displays through Mini DisplayPort. 

However, there is a company called DisplayLink that makes software drivers for USB video adapters. They also have links in their store to Mac compatible, DisplayLink approved USB display adapters. One of my coworkers uses this to connect a MacBook Pro to two external displays and a TV in his office. It uses the extended desktop feature for each display. It's a pretty sweet setup and works flawlessly. 

I see no reason why this wouldn't work for you. Good luck!