I would pick the one with the best personality. Paint jobs are great and all, but I keep snakes as pets because I love snakes. You could put a pretty paint job on a donkey, but I still wouldn't want it as a pet.
Don't get me wrong, as humans it's only natural to be drawn to something that physically appeals to us. Whether it's a spouse, car, clothes, whatever...physical appearance is a factor in which we choose.
I guess all my babbling can be summarized by saying if it was me, I'd keep the one I enjoy most as a pet. Beauty is only skin deep.