I have an idea. Add 2 more chapters. Dark Angels, and the Iron Fists. You could also make other chapters, weapons, or other types of marines, like Apothecaries.
And...

How about making mods for other aspects of 40k? Orks? Chaos? The Astra Mlitaurm? the Death Korps of Kreig?
This mod is cool, but i think it could use an update, and its own category, if you actually see this message and add my suggestions.