I, too, am visiting Vancouver in early September! I've been trying to do some research on the matter, but as far as shopping goes I plan to look into:
Inventory
Roden Gray
Haven
Gravity Pope
Nouvelle Nouvelle
Lark
Old Faithful Shop
I visited Vancouver last year and was only able to make it to Roden Gray and Lark. Jonathan + Olivia was also a great shop, but I hear has shut down since I last visited

If anyone else wants to chime in on VAN shopping/local dining, please feel free!