hhmmm, perhaps if you include dawnguard you could go for a "underworld-esque" feel? Join companions and do that questline, afterwards starting dawnguard have serana turn you (like michael was turned to save his life.) becoming a hybrid, shunned by both vampires and werewolves the two of you life in the woods on the run but then decide to strike back? Or something to that degree.
YES! I can finally post this here for a reason, wait past the ending, you'll see.
http://www.youtube.com/watch?v=LciyFOKgMUQ&list=PLiqPWOQJG1tJyqZ_ml7Z0wzObLikLqRBj
Sadly, it wouldn't let me embed it
Here's a thought for you. As someone mentioned earlier, werewolf is very much a warrior form whereas Vampire Lord is mostly mage. If you want my reccomendation, either play as a battlemage and embrace those forms as the highest aspect of your craft, or (my choice) play as a thief in human form to balance out the trilogy.