Hi there, LED! And CONGRATULATIONS! I have a 2-year old boy, and he's such a cute little handful!
I would try Rosesare- she has a friend who does her embroidery, so she might be able to hook you up.
I also have a local person here in Minnesota, she's not a pony person and she will charge for it, but if you can't find anyone else, I can ask her. I had symbols and eyes made for a giant plush, and she charged about $25 for all 4 of the patches. I'm not sure if the pricing has changed, but it should give you an idea.
Congrats again!