I talked to a friend of mine about servos and he was saying that we should really use metal-gear servos. While these will be a little more expensive, they will have a lot more strength. This is a good idea because (especially in the bunny-ear case) there could be a lot of strain on the ear
Here are some servos available from a shop in calgary: http://www.solarbotics.com/catalog/motors-servos/servos/1/
Remember, at the end of the day some servos have to be attached to, or close to, the ear.
I personally have never really played around with a servo mechanism, so there is a lot of limitations and such that I am just… clueless about.
My initial choies for servos are below, but I may as well just used a random number generator to figure out which ones I like: