On the island have a look at Bella Pacifica in Tofino, Miracle Beach, Salmon Point in Campbell River, and my personal favourite, Telegraph Cove near Port McNeill (shout out to Stubbs Island Whale Watching).
Some beautiful country once you hit the mainland and drive east on 16. We liked Francois Lake Provincial Park.
That's quite the circuit if you decide to come down 97 and then back over to Jasper and Banff. If you do decide to come down 97 stop in at Barkerville (
http://www.barkerville.ca/). Are you planning on going through the Okanagan wine country to get back to the Rockies? Alternative may be to stay on 16 through to Jasper, and then down the Glacier Parkway to Banff (Hwy 93...absolutely SPECTACULAR drive).
One tip, if you intend on staying in the BC Provincial Parks and National Parks watch for the opening dates for reservations and pounce on the reservations systems. We did 10 nights in Banff and Jasper in August but I had to book way back in March to get back to back bookings and consecutive nights. We live in Vancouver, BC--anything within a day's drive will book up fast.