What exactly do you mean with "making them MC2 ish ?" Despite the fact, that the original MC2 mechs were quite low on polygons, they are very close to the canon design, and to be honest, I do not really want any "made up" stuff in there also, no offend

Besides that, the original texture were RGB coded. Karl can tell you more how to create those type of texturemaps. I don't think that there is already some sort of tutorial, except the text that magic posted over at DSC
If you aim for the champion mech, well, if you build the mech for the retail game, you should keep it below 1500 polies. We aim for something around 3K for mechs in the new engine, once it will be functionial. So if you stay close to the original maybe you already want to build it with a little more detail (though I have learned, that you can create reallly good looking mechs with around 2500 polygons)