Well, for your tactical squads, you can malke the two parts chaos marine, one part regular space marine and one part DA veterans... As for the rest, use DA characters and chaosify them with some bits from here and there.
Also, you could mix loyalist termies with chaos termies, and as some DA termie bits to finnish it off. Might look awesome!
no they are a group of dark angels that fled together swearing that the day the lion returned they would return to the rock to plead forgivness does that sound fluffy enough. i really only play warhammer 40k because of the storyline. its awsome!