Welcome to the site! You are heading down an incredible road with your plans!!
How long will you be in Quartzsite? A couple of us from the site will be there next Thursday. It would be great if you were around so we could all meet and swap stories!
This is a great time to be buying a rig. Because of the latest economic struggles everywhere, the RV market is really soft right now. There are deals to be had. First thing to do is to figure out what you need. When you go to Quartzsite, walk through as many rigs as possible. Talk to a lot of fulltimers about what they like and don't like about their rigs. Floorplan is one of the most important concerns. You will be driving it around, but most of your time is spent actually living in it. Make sure it is liveable for you guys.
There are a ton of discussions on motorhome vs. tow behind. Again, really up to your needs. I usually suggest if you have a big truck that can pull a tow behind, that would be the least expensive way to go. If you have to get a truck and a trailer, then it is a coin toss. Pick the one that works best for you. I have a motorhome and tow a Jeep, and love the setup. However, I have never owned a truck and trailer, so couldn't even begin to tell you that mine is the "best". It is the best for me, so that's what counts ;)
Hopefully we can meet up in Quartzsite! I have a couple of blog posts here on NuRVers telling about our adventures there so far. We are away right now, but will be back next week.
Welcome to the site!
--kev