I'm getting a 300 this weekend (2' longer than your 180) and will be doing a community SA/CA tank, here's my partial stock list so far:
Herichthys Carpintis
Parachromis Motaguense
Nandopsis tetracanthus
Parachromis Loisellei
Parachromis Friedrichsthalii
Crencicihla Lacustris
Crencicihla sp. Cobra
Do what I did go here:
http://www.cichlid-forum.com/profiles/
and browse through the profiles and see what fish you like, the profiles have max size and pictures as well as other information about the fish.