I was contemplating starting a bretonnian crusader army, templar knights all white with red crosses and instead of damsels i was thinking of using priests but i dont know what a good priest model, preferrably on a horse would be? Does anyone know of any priest models?

The Luther Huss empire model is a cool preist model. Although his horse is a little different than Brets.

Luthor Huss or any Warrior Priest model can be used for a Priest, don't forget you can just Bitz order an extra Bretonnian Warhorse for him. Also, take a look into some of the Daemonhunter/Witchhunter Inquisitorial Retinue members. They might have some icons on them that you need to file down, but some might be what you're looking for.