To the best of my knowledge, you will NOT be able to achieve the finish you want with stainless steel. If you want the master polish blue (as in, Colt Royal Blue/Carbonia) you'll have to start with a blued gun. And, as I mentioned before, you will have to pay a bit of a premium for the work. But--once you see that blue, you'll go ga-ga over it. Take a look at Ron's Gun Restoration website; click on the Finishes tab, and select the link that says, "What is Carbonia?" Look at the grip of the Colt SAA near the bottom of the page. Is that not drop-dead gorgeous, or what?
http://www.ronsgunshop.com/carbonia.html