APW/Cogan does offer black chrome, but they say theirs is a more matte finish.
Techplate offers a glossy black chrome, but it seems to be best applied over another plate like hard chrome.
Note that black chrome is not a very durable finish. It's about equal to standard bright nickel.
However, as done by Techplate it should meet your need.
http://techplate.com/black_chrome.htm