biped with arduino

I would to make a biped with arduino. Has anyone made biped with arduino? I need to know how many servos we can run with arduino. I would like to run 8 servos for biped. Also, I want to where is best place to buy cheap servos. I see there is so many kind of servos and I was not sure how strong do we need. I don't want to make so big. I was think to make about 12 inches tall. Please give me some link that I can take look and study itl.

Microguy