What about buying used? Do I just make sure it's a Pro? The Mitsu/Koshi dials are only for Pro size correct? Then I could just buy whichever hands I wanted. But getting the Pro with the panda already in place would be the main objective. Are people selling fakes of these that I need to watch out for that are good enough to trick a trained eye?
I'll try to answer your questions and hopefully answer ones that you haven't asked so as to guide you through the process and not have multiple posts of questions asked over and over again.
-Yes, the Mitsukoshi dial will only work with Speedmaster Pros with cal 861/1861/863/1863/movements. I guess technically they can also be used in Speedy Pro Mark II's since the dials and hands are interchangeable, but I've never seen or heard about any mods that've been done with a Mark II.
-Speedmaster Pro hands come in a slew of different colors so yes, you can pick pretty much any colors you want. You just have to make sure you get the correct hands for each function and subdial as the posts are different sizes.
-Getting one that's already been converted would save you the time/effort/hardship of sourcing the parts and a qualified watchmaker to do the dial and hands swap. But with any watch purchase you will not know the full history of the watch for sure but will have to take the word of the seller.
-It's very hard to sell a fake of the dial since it has such particular design elements that are hard to replicate as long as you know what to look for.Study up on pictures and posts on other's project watches so you know the elements by heart.
-However, technically all Mitsukoshi mods are "fakes" since the dial is NOT original to the watch from the factory
-The dial and hands will be available forever but being able to purchase them is another matter. You will have to purchase either directly from Omega or from a watchmaker with an Omega parts account. Omega NEVER sells individual parts unless they confirm you own the original watch that the parts are made for, and I believe they extend a similar policy to watchmakers.
-Truth be told it's very improbable that any new modded Mitsukoshis will be made from now on. The parts supply of the dial and hands has dried up due to the tightening by Omega. So if you really want one you'll most likely have to purchase one that's already been converted.
Sorry for the bad news, but it's the foreseeable future.