If you want to stay in Brisbane, I'd go see Redcliffe Aero Club, (new CFi Mike Loughnan is a top bloke), do your initial rating in the Party Bus (even cheaper and they are actually used in GA, as opposed to DutchOvens, SeminHoles or Doominds) and then add the C310 on afterwards.
You'll have another type on the license and you aren't going to be let loose on your first twin job until you have 25 ICUS anyway. If you want to go Baron, Daedalus at Archerfield have a B55.
If you're current (and competent) at twin procedures, it shouldn't take any more than two hours flight to do a type conversion.
