I know someone makes them, they probably all do, But to tell you the truth, I have used regular tuners on all my guitars, without string trees, with great success. I think the secret is to have a well prepared nut, Some of my builds have locking nuts, the others are just Warmoth prepared corian nuts, never any problems.
String trees are installed on a lot of over the shelf guitars, just as a precaution, just like action is set high on a lot of guitars , just for a buffer.
If you can do your own setup, and can recognize when and why a guitar string is jumping out of the nut, then you install a tree. But otherwise, don't do it.