UA: Can purchase Trade Units bypassing building requirements.
UU: Establishing a fondaco in lands of other civilizations gives a +5 Diplomatic modifier to Amalfi (the Fondaco has the same yields of a Town, so it's a free Town after all)
More unique components
UU2: Saettia
A unique Galleass replacement for Amalfi.
It is weaker but has double movement along the coast, and can carry up to 3 non-combat land units generating

Great Merchant points while doing so.
Can cross oceans once its upgrade is available.
UB: Paper Mill
Unique Amalfitan Windmill replacement.
In addition, +1

Production from Scari, Lumbermills, and Logging camps.
+2

Production from Civil Servants in City.
Provide 1 Paper plus 1 Paper for every 3 Paper Mills in the empire.
-1

Unhappiness from

/

Distress.