I'm not even considering Alcatraz in my tiny city. I can't see any way to compete militarily with 16x16 squares anyway. I'll just be building the minimum military to get through the map, supported by a Zeus. The only other GB that looks useful is the Lighthouse (as mentioned above somewhere!).
There are 3 of us that have formed a small guild (no heavy commitment required) to play 16x16 cities on Cirgard - If anyone wants to join, get in contact with me there. I think we will need a few more members to help produce a selection of goods to aid progress.