Those are excellent too! I would suggest the Brigades from Red Box Games, but I doubt they would scale up with these Citadel miniatures. Do you use inks on the skin or layers, or a combination of both?
I had hoped that the RBG stuff would be a good match but unfortunately they're not. Height is fine but the proportions of Tre's sculpts just don't fit with these old Perry's.
Skin is just layered paint although sometimes I'll add a quick very thin glaze of ink or more likely these days thinned down GW Wash at the end just to bring it all together.