The South West Carpet on your list is pretty much the equivalent to what you are referring to as a Coastal. You will have to purchase your snake in WA as you can't import snakes into WA from other states.
As Mertle mentioned above, your snake will be better off in a click clack for a period of time. They like the smaller enclosures when little and big ones can be quite frightening. This just means you can get your little baby before having your lovely big enclosure finished and by the time you have your babies feeding/shedding/temperament sorted out and stable, it should be close to ready to go into the new big enclosure.
PM Antaresia Lady. She is in WA and can point you in the right direction for breeders and supplies you will need.
Congrats on your choice of pet and good on you for taking the time to learn.
