There isn't a trainer that will make your future plans any easier or harder, but there are trainers than make it easier and harder to build your flight skills. The RC hobby is truly two different skill sets- building and flying. I suppose it's up to you which to develop first, but I'll suggest flying since that saves you a lot of repairs. There are several clubs near Seattle. I promise you, the driving time to a suitable flying site where an instructor is there to help you is much less than the repair time you'll have to put in by flying in an unsuitable location by yourself. Even a simple .40 size trainer needs a lot of space to fly safely in. I'd say a minimum of 1500 feet long by 500 feet wide assuming a suitable landing strip is located in the middle of that.
As for what to buy, have a look at the "what's available" sticky at the top of the beginner thread. Do go ahead and buy a 6-8 channel computer radio though. The simple ones that come with RTF airplanes are just money thrown away. Just so you know what you're getting into, you should budget about $500 plus your club dues and AMA fee to get everything. That's not the bill for buying all of the best stuff, but just new serviceable equipment that won't break and frustrate you. You can save some money by going used, but there's always a gamble there.