Karla, I would trapunto the horses. Just put a layer of batting on the bottom, and from the top, sew around the horse shape. Then trim the extra batting away from the shapes. Then when you make your regular "sandwich", outline the horses again, and it will make the heads stand out. It's actually easier than it sounds, and since you are outlining, you don't have to try to sew through the thicker suede. Then just SITD for the rest of the barn details.
Here's a good video showing what I mean for the trapunto:
http://www.youtube.com/watch?v=5_wgE74Mro4
This is the first of about three. It's actually easy to do, I did it on a little quilt I made.