adequate filtration on a non reef system does not need weekly water changes. the fish can stand higher nitrates etc then a coral ecosystem.
my mate had 1 epaulette shark and bamboo and a few other decent size marine fish (blue spot ray, huge leopard moray, a volitans and some nasty piece of work triggerfish) in his old 10x2.5x2.5, did monthly 50% water changes (using Fremantle ocean farms, and the tank was running for about 3 years until he sold it all (moved house and his mum said the tank was too big - which it wasn't a bad size).
port jacksons are average, very inactive compared to other species and there a temperate water species.
I seen vebas had a small tassled wobby a few months back, ripper looking fish.