I work in the IT industry here in Seattle and have now for about 15 years, outside of Silicon Valley you won't find another location with more tech jobs. Even through the high unemployment rates of the last decade it has remained pretty easy to find tech work here as long as you are a bit above average from a skill standpoint and are not completely socially retarded as many IT people are. The area defined as the "East Side" which includes areas like Bellevue, Redmond, Issaquah, and Bothell will be the best places to look for work but you wont find that those areas have the friendliest medical Marijuana laws (They won't mess you for growing legally but they will if you are selling and they do not allow dispensaries.) The city of Seattle itself has the most relaxed city laws when it comes to Marijuana of any area in the state (you hear people talk about possession not being a crime in Washington, that is not true but it is inside Seattle city limits.) but who the hell wants to live in downtown Seattle? I think you will be able to find an area that suits your needs just fine but if you want access to medical Marijuana through dispensaries (I am talking clones, edibles, and dry meds) you will want to stay in the Seattle-Tacoma Metro area (From the Puget Sound on the west to as far east as Issaquah, and on the north from Marysville to Tacoma on the South end) unless you plan to make a long commute for both work and dispensaries.
If you want IT work and don't want to struggle looking for it you may as well just forget about Vancouver, and working in Oregon is not worth it unless you live in Oregon. However living in Oregon and working in Washington works out well for some people (these working/living scenarios are based on taxes.)