I'm with you Wheels Down, as the A318 & 19 have/are being discarded by many airlines as they upgrade capacity and can be picked up for a song. The A318 not so much, as not as many were produced while most were scrapped for parts as they got more worth than an operating unit... but it would be ideal IF sourced. Same PCNs as the already approved A320 airstrips.
Other options are interesting too - the MRJ; SSJ and of course the EMB series but I'm abit suss' about those as an operator tried with those and is no more (Maybe it was the management of said Company
)
What does concern me though, is the sad fact that Australian Aviation has come to this disgraceful point mentioned above, stymying any progress or efficiencies :
I am not sure I would want to be the first in Australia to introduce a new type with the regulatory pain that would cause.