Since you're heading east, you should stop in Revelstoke along the way. Ride Keystone Standard Basin, Frisbee Ridge and Martha Creek (Sale Mtn). Stop in and do a lap of Mt 7 in Golden on the way through as well. It's much more suited to a DH bike, but driving through Golden without doing a lap would be a serious mistake for someone who may never return. If you skipped everything else between Pemberton and Banff, but hit these 4, you'd have made the best of a good situation if you ask me. Not that there's nothing good anywhere else, but these are truly unforgettable gems and offer a broad selection of styles with high alpine flow and technical gnar. Epic gets thrown around a lot, but Keystone's views are truly that. Frisbee Ridge is flow central with 12 km of nonstop DH high speed ripping and when added to Frisbee DH a little further down the road which is steep and technical, it makes for one of the best AM rides on the planet. Martha is 5000ft of vert, so how can you go wrong; from alpine meadows with sweeping vistas and awesome rock sections, steep gnar and pinned technical singletrack that never seems to end, it's pretty hard to beat. Mt 7 is my favourite track in the world. Nowhere else can you go that fast for that long over very rough terrain with natural doubles everywhere.
When you're in Banff, ride Upper and Lower Stoney Squaw at Mt Norquay. Good times to be had there too.
Jack the Ripper in Pemby is pretty sweet. So is Stirling on Cypress. I live in Squamish and there's some amazing stuff here too; it just doesn't have the 'epic' feeling. More of a fuck yeah feeling.
I'm an Aussie too; used to live in Brissy and raced DH there for about 5 years. Hit me up when you're here and I'll show you around Squamish if I'm around.