I'm also very interested in this thread as I currently have a 5ft tank and want some ideas on what to put in it.
To give the OP some ideas, mine currently has bala shark, tandanus, scat, saratoga, featherfin catfish.
I'm looking to put in a yellow-finned eel-tail catfish and a black salmon-tail catfish.
I wanted to put in an Eel of some sort, but have no idea what type is available in australia and grows to a decent enough size that won't hurt the wallet, maybe someone who knows can let me know?
Thanks in advance.