Hi Jamie, not a rocking horse suggestion but have you ever looked at the Dentzel carousel web site?
A number of free animal "coloring book" pictures that might suite your purpose as far as fancy design.
http://www.dentzel.com/
The colouring book link is about half way down the page or :
http://www.dentzel.com/coloringbook/samples.htm
make sure you look at the bottom of this page for further colouring book pictures.
Also here's a rocking horse carving web site that might also be of interest, it's in Canada.
http://www.gordonswoodcrafts.com
OG