I think if you started off a new thread with an appropriate title to attract some interest you will recieve a lot more responses. I also think you need to to be considerably more specific as just about every component of a model steam plant can be purchased from numerous suppliers around the world.
As for valves I use Modelbau-Niggel, he produces some of the best valves around with flanged connections as opposed to compression fittings. He also produces just about the best displacement lubricator money can by with a glass cylinder, drain valve and needle control valve, all completely dismantlable. He is in Germany.
What kind of regulator are you talking about? Steam pressure, gas pressure, steam control valve? As always a big subject so narrowing it down will generate more answers.