I have the gargoyle necklace set (As in the two you get from that same mission) and same for the Ring of the Beast set but haven't ran into any more side missions involving more artifacts, just normal ones and the ancient vampire body parts.

There's the fully upgraded bloodstone chalice. That's about it, though.

The two rings and the two necklaces and the upgrades for the bloodstone chalice are all the artifacts..unless you count blood potions.

Then that svcks. I was at least hoping for a nice hood or something.

You can get blood hawk stuff in Harkon's room that you can enchant if you want, they are in one of the locked cases, you can enchant them if ya' want..they are one of a kind items also a werewolf pelt thats one of a kind even though it makes no sense since there are random enemy werewolves at night..but they dun' drop a pelt.

..and the Vampire hood is only available on the dawnguard side supposedly as a random event, I'd recommend getting the shrouded robes' hood from the dbrotherhood if you really want one.