Doubt anyone would supply them in Bunbury. Definitely a special order item. Get a recent street machine or performance car mag. Ring around and get some quotes from companies over east who could freight them over to you.
Are you after a street legal set up?
I'd get the 15x10's for the rears. I had 295's on my previous wheels and they need the wider rims, otherwise they baloon out too much. 295's great choice for the phat coupe!
15x4 front runners would be nice for racing, but a little illegal in Perth.
Here's a comparison of my set up for you to see. I have 15x8.5's on the rear with a 3.5" offset (to the inside). ie: they have a 5" deep dish. They have 265 Yokahama's. On the front I have 15x7's with 245 T/A Euros (these tyre's are no longer available). Nobody seems to make a 245x15 anymore. Plenty of 235's from memory - which are fine, or you could even go skinnier. Still a little room in the rear guards (which the old 295's and 15x11's filled out nicely). A 15x10 with a 3.5 rear offset would look like this but with a dish that would stick out and extra 1.5 inches (ie: 6.5" deep).....nice for the coupe.