If you would be purchasing your first RV and know little about them, it will most likely never be your last. You will get your feet wet with your first one and then you will start thinking about features, layouts and size of what else is out there.
When we bought our first TT, an experienced owner at an RV repair shop told me that it will definitely not be our last and I thought to myself he's totally wrong. Well, that TT lasted only one year until we decided it was too small and cramped... Probably lost over $5K in depreciation and mods & upgrades.
Renting a CLass C may seem expensive but compare that to depreciation and other expenses of buying something. That is one reasonable option plus you can tow your car. If getting a TT, I would get something with a sofa in it and at least one slide so that the family can all sit and watch TV or do whatever together. If doing a lot of travelling around the PNW, there are lots of hills (6-7% grade in Cascades) and you don't want to have too big a TT for a 1/2 ton TV (if 1/2 T is what you get). Something with bunks would be better than setting up the dinette every night for sleeping, except the could add too much weight (longer TT). If buying a used RV, be very wary about water damage as it's often difficult to spot without testing/inspection by an expert. Before paying for an RV, I would hire an experienced independent RV tech to go over it.
I would suggest going to an RV show and wander through the various class Cs and TTs to get a sense of what will suit your family.
Have fun and drop in for a visit at our CG in Birch Bay, Wa. :) The state park there is excellent camping too.
