I put together the following list after a while of thought and browsing of forums. Not supposed to be geared against anything in particular, just a sort of balanced list.
No AC's, I know. I'd like to expand it to 1500 at some point, but right now I've got two blister packs of swords and two boxes of cruisers (for a total of 6 swords and 4 cruisers). I've already assembled a Lunar and a Gothic.
A few different options I'd been thinking of to get some AC's:
Drop a Lunar and 3 Swords for a Mars.
Drop a Lunar and a Sword for a Dictator.
Just wait to get AC's till I expand to 1500 and get an Emperor.