Get the guns and gear after you come back from seattle.
I forget the name but there's an outlet area thats in seattle with things like oakley store, nike store, **** store, etc.
Then theres also the other place south of seattle (forget that too but I think it's called portland or something). Some really nice shopping there.
As for Vancouver definitely hit up the Grouse Grind, nice workout and nice view at the top (going down it's only $5, don't pay to go up it's like $25 or something) (budget at least 1-1.5 hours if you're fit, otherwise the aveage time is something like 2-3 hours, also don't wear sandles, try for runners, or hiking boots, but try to wear those cross hiking/running *****).
I forget the name but the Baden Powell trail I think has a hike up to this mountain (I think it's called the 3 sisters or lion peak or something). Also of intrest might be the BCMC (BC Mountaineering Club) trail that goes up the Grind but I'd suggest use the trail provided by Grouse.
Link to the BCMC trail
Shopping wise, Metro (metrotown/metropolis) is probably the place to go (Burnaby), otherwise for a bt of a change Arberdeen and Yohan (Richmond) are some nice alternatives, or Crystal Mall right across the street from Metro.
In vancouver if you have a lot of cash to burn then Robson st. might be one of your stops a lot of high end stores there and even if you don't have a lot of cash might as well take a walk and window shop down the street.
Try to avoid Main and Hastings. Not like theres anything cool there anyways (well except for gastown and chinatown).
Gearwise Daves is the place to go (a bit of a drive but well worth it, it's in New West), otherwise Gorilla Surplus (East Van) is a closer alternative.