With your max tow capacity at 7200, you are going to need something with a max gross weight around 5800 - 6000 lbs. There are a lot of really good lightweight models available that can fit your need. Heartland Wilderness and North Trail are both lightweight. There are many others as well. Being on the west coast, Artic Fox might be something to consider, although they will weigh more. As for wood, many have aluminum framing or a combination of wood/aluminum. Very few are wood free totally. If you do go the used route, just check it out well before you buy. If you are not 100% sure on your tow vehicle, have your dealer run the vin# or use one of the online databases to find out for sure. Good luck with your search
