If you want actual paper copies of maps for the Coast MOUNTAINS , the best place is the GSC on Robson Street in Vancouver, tel 604-666-0271 (they can probably send you stuff). MEC and other outlets have SOME, but usually only the popular areas.
However, everything is online now:
http://maps.gov.bc.ca/imf/imf.jsp?site=bc_basemap
Click on "layers" to get elevation and play around with scale to get the right one (usually 1:20'000 or 1:30'000 give you the best relief)