Having suggested the armor slots as the easiest way, I don't think it would actually be so very difficulty to implement some kind of crafting mini-game that worked similar to the face editor.
There could be a series of sliders for the various sub-parts of the armor, with presets that work like the face editor's mouth/hair/eye sliders. Once all the sliders were set, and the color chosen, the armor would be "frozen" as a single piece. Since it would all work on a system of presets, from a limited set of meshes/textures, it wouldn't necessarily create problems like clipping, and there wouldn't be the imbalance you'd get by having a lot of extra clothing/enchantment slots.