Bukkit

What is the enhancement in mind? How should it look and feel?
I'd like my players to have to tame horses the old fashioned way (break them) and then have those horses added to their stable.  In other words, when they tame it and add a saddle, I want it to become owned by them.  I don't want them to be able to rename wild horses or horses they don't own, but as soon as they own the horse, they should be able to use a nametag on it.

Please provide any additional information below.