I'm also planning to have a crack at making some.
I bought some from AR which are great. Topped up with a few more from RDG or Chronos, but there was a fair amount of variability between them, some perfect, others not so. The AR ones are much harder steel which is good unless you want to mill a bit off them so you can use 12mm shank tools.
Videos make it look so easy, but from experience it never turns out that way (for me).