You should check out BavGruppe Designs out. They have a whole list of installers on their site that are approved by them so you know the work will be good.
https://www.bavgruppedesign.com/find-an-installer
Out of all the headlight installers, my recommendation is Accorsi Engineering who is one of BavGruppe Designs BEST installer. The paint is not rattle canned, rather he uses an actual paint gun to paint all the pieces and he guarantees the rings to be installed straight and true (a real problem some installers have by installing them crooked). Here's an example of his work.
https://www.instagram.com/accorsiengineering