Good chance for some nice steelheading in that period! Most rivers have good access, but remember: the easier the access the more anglers, especially the local anglers in the weekends. Please note that most rivers are Classified Rivers as well and you need also a Steelhead Stamp! Guides can be very helpfull but are not obliged. Try the Zymoets, Lakelse, Kalum to name a few and also pay a visit to nthe local tackle shops. The have lots of info about 'their' rivers, popular flies etc.
I will be in that area at the end of September, but I promised to leave a few steelhead for you Scott!!!