Like Onefuryz says the countess is a good place to get runes, but not just sure that you can get Zod from her. Just make sure you do it in single player games as with more players you are more likely to get drops from her item table and not her specific rune table (she has a max number of drops)
Hellforge quest should drop a decent rune for you. Unfortunately only the once.
I've heard that the council (Travincial) could be good for runes. I'm trying to work through Hell so that I can do the cows... Due to the numbers they should be good for a few drops !
Wow the Countess has worked great so far. I have found a Thundergods Vigor (anyone need?), Dol rune, Io rune, and Sol rune. My merc found the Vigor with her 112% MF. Thanks for the help guys, and I sure hope I can find a Vex or Zod.