I think the best items for cleric, if you're gonna became a bishop, are:
Weapon: Staff of the Ogre Shaman. (drop from ogres)
Armor: Thaumaturgist's Robe. (crafting item, recipe from the house in the road)
Misc: Holy book. (drop from any mob in d2, also from Sanev)
Accesory: Amulet of Magic. (drop from The Protector, in d2)
Helmet: Hat of the Witch Circle. (drop from the Ancient One, in d2)
Hope it's useful.
P.S: to make thaumaturgist's Robe, you will need searing blood. It drop from any boss in d2.