Who makes, or where can one get, the plumbing accessories which deliver a stream of water at a controlled temperature ?

I will be building a very simple darkroom. I've been developing film in a tiny bathroom for the last 6 years, and before that (in the 1970's) I used a small garden shed, erected in the basement, with with no running water.

Are there sites which show a variety of plans for darkrooms ? Someone mentioned APUG, but a quick search did not reveal anything for me. Perhaps I missed it ?