They decided against making an AD Chalice upgrade in favour of making Manamune better (unfortunately). Perhaps Mikael's Crucible would interest you though? It's a bit of a support item, I digress, but Urgots are renown for their tankiness rather than core damage so where it lacks in offensive stats he may not care:
+40 magic resist
+9 mana regen
UNIQUE Passive - Mana Font: Increases your mana regen by 1% per 1% mana you are missing.
UNIQUE Active - Removes all stuns, roots, taunts, fears, silences and slows from a target ally and heals them for 150 + 15% of their missing health. 180 second cooldown. (You are a valid target, but it cannot be used while CC'd).
Recipe: Chalice of Harmony + Sapphire Crystal