I have seen plenty of dark elf models used as vampires- particularly the plastic sorceress, and the elf swordsman from mordheim (Aenur, Sword of Twilight) being particularly good examples.
Myself, I have used Dark Eldar as vampires- particularly the Lahmean Poisoner.
Generally the right paintjob is all you really need (though with the Lahmean I had to file off some generator looking backpack things).
Heck, shadowblade doesn't even have his mouth or ears visible, you you don't need to worry about him not having pointy teeth or having to file down his ears.
I think a predominance of red & black on the model, particularly on the armour, or some kind of freehand with skulls/bats involved would help sell the idea that he is a vampire though.