check out supreme coffee machines in burswood
they have a reasonable range and im pretty sure you can test all the machines they have on teh floor. I was in there this morning getting some parts for a cimbali liberty, which they had in stock!!! everytime i have been in there the staff are always really helpful.
I have no connection with them, just a happy customer.
there is another place in mt hawthorn, corner of loftus and scarb beach road I think, not sure whether they have test machines though.