Rio Rancho Armory has a guy who does stippling and cerakoting. I haven't personally had anything done through him, but have seen a couple pistols in the shop. Ask Nash, the owner, and he should be able to get you more info.
I've sent a few pistol frames to a guy called "stippgrips" on instagram and have been very happy with his work.
Here is a g45 that stippgrips stippled for me: