I'll do some research, seems like Muslim Spain is already done, but if you're going to do your own, I suggest Sayyida al Hurra as the personality for the civ.
I'd suggest Basque Whalers as an UU for the Basque, replacing the Work Boat, they were the first people to commercially hunt whales and had their golden age during the 16th century, whaling all through the atlantic and there's even myths that they went hunting up to the Americas in the 1300s, fun stuff.
For leader I suggest Antso Gartzeitz III.a Nagusia, or Sancho III the Great if you don't feel like using Euskara names...
For an actual military Unique Unit, I'd suggest either the Chapelgorris or the Vascongado Tercios...
For Catalonia, I suggest James I the Conqueror as the leader, and the Almughavars as one of their UUs.
Another interesting fact is just how old the Catalonian Parliament is, roughly 11th century, so they may have some bonus related to the World Congress or something like that, I imagine Catalonia as a cultural powerhouse, with their peak strenght in medieval times.
Both Catalonia and the Basque country were the centers of Spanish industrialization, so there's that too.
Galicia... should be a naval civ, haven't found out much more than that yet.
) with different time lapses
