Wedding on horseback?

Sounds cool, doesn't it? Looks like it can become a reality for Kevin and I. We are to be married by a Catholic priest this year to make everything legal (Catholic-wise). Our totally cool priest is working out a way that we can get married outdoors on horseback. I can't think of a more perfect way to seal our lives together than with the kids and horses all present. Now the big question...what to wear? What does one wear to be married on horseback? Definitely not a dress (besides I am not the dress-type person...been there, done that!). Any ideas?