Thanks for the suggestion. I have a bunch of the Wargames Factory horses (the bare ones) already. They fit with the Hinterland horses pretty well and it would probably be just as easy to start from nothing.
I don't think Ebob sells bare horses unless you are licensing them for a commercial range, which would be my best conversion option.
If no one makes the correct horses, WGF is probably the route I'll go. At the very least I should try to convert one over to see how it goes.
Thanks!