Rogue Trader, a 40k RPG (exact same system as DH in terms of d10's, characteristics, etc.), has, in its's extremley limited Xenos section, a profile for an Eldar Corsair. Creatures Anethema has profiles for a Dire Avenger and an Ranger, along with profiles for an Eldar Sniper Rifle, a Shuriekn Catapault, and maybe a Shuriken Pistol. Other than that, its all going to be fan made stuff.