Considering that you're from Sydney Australia, ur best bet would be to get some decent size clown loaches. Another option u can get from your LFS (if they don't have it, they can order it in for you) are some Hoplo cats. (Just very big versions of corydoras).

Interesting suggestion of Hypancistrus sp..... Now at the price they are in Aust, u wouldn't risk them with those other cichlids!!! LOL!!!

Another possible addition are the Dekeyseria pulcher (L16 which have just been included into the Aust import list recently.

kev