Well, Daveyspawn, A couple notes that might be of interest.
First off, Dol Guldur isn't just some spooky wizard's tower to raid. It is a minor fortress of Sauron. Even after Sauron withdraws to Mordor (after The Hobbit) there will be armies of orcs around the place. Plus Big S left a Nazgűl in charge in his absence.
Just so you know what the player characters will be up against. Not that they will know anything about this, mind you. Mysterious persons hiring people to recover rings of power might very well neglect to explain the magnitude of the task.
Secondly, there really aren't many ancient Dwarven cities in the Misty Mountains. Other than Moria, there is only Gundbad, at the northern end of the range, and that is both infested with orcs (of course, so is pretty much everything else in the Misty Mountains) and much farther out of the way than Moria or any of the regular passes. If you don't already have it, check out the Moria boxed set from Decipher for good Dwarf and ruined Dwarf city info, regardless.
Good luck!
-Chris Landmark
"Was entstanden ist, das muss vergehen. Was vergangen, auferstehn." -Klopstock & Mahler
"Only liberals really think. Only liberals are intellectual. Only liberals understand the needs of their fellows." How much viciousness lay concealed in that word! Odrade thought. How much secret ego demanding to feel superior. - Heretics of Dune