I have other manips I have done with credits to stock providers, they are legible and on the finished image.
I'm 100% understanding of your conditions, and if you require credit for the stock image it can't be on the coat image (that's the rules, sorry :/) but there's a personal profile where I can upload an image of the coat and give you the appropriate credits there as well.
This project hasn't even been started (heck, I haven't even finished my current one--I'm getting there though, xD), so don't worry about rushing to get back to me. Sorry if this sounds weird, by the way, it's my first time talking about stock references for lineart.
OMG what a beautiful horse!
I wish I had a horse . . . .