Lucky for you, you leave real close to the best place in the world for that. Make your way up to Sacramento to RV Doctor George (RV Doctor George of Sacramento, CA - RV Parts - Service
). They have EVERYTHING RV related, most of which is used. Imagine a pick-n-pull and a warehouse for anything that was every put on an RV. My friends who did a van conversion got most of their things from there. (I personally am fine buying new for everything, but that's just me personally).
You will not find a better place in the country that matches what you're looking for.