I just reread your post and realised you’re going north, so that discounts the SW and probably limits your time around Perth?
Here are a few of the best steep problems around Perth at V6/7:
Pipelines:
Secret Goverment Ninja Moves V6
Hay Stacks V6
Boulder Rock:
Beta Boy V7
Watermelon and variants V5/6
Millar’s:
Shambala V7
Savage Bliss V9 (epic problem, worth at least looking at if you’re there).
Bouldering is pretty new around here, most of the areas have only been developed in the last few years, and as such it’s hard to pick out ‘classics’. The rock is mostly granite and tends to be vertical to less-than-vertical, with some impressive aretes but fewer steep faces. Anyway, have a look at the pdf topos and make up your own mind!