I'm a newb from the Portland, OR area.

My wife and I have been wanting a camper for the past 10 years after we had to sell our older Chalet. I loved camping in it but had to give it up for a number of reasons. Kids, family, work, etc. Now the youngest is off to college and my wife and I just bought a Subaru Outback that's capable of towing a camper so I'm looking for a way to get a camper without spending an arm and a leg.
Don't know why I haven't noticed TD campers before. They're perfect for the two of us. We're both in love with small houses and the TD is about as small as it gets. Plus I love the design, and the possible woodwork, and, and.
I'm going to lurk for awhile and try to soak up information before I start the design/build process. Fortunately for me, there are lots and lots of designs to choose from, thanks to all of you generous folks!
One question before I disappear into lurking. I want to build around a Queen size mattress. That means 60" width for the inside of the TD. Has anyone ever designed for 60" inside dimension on a 4 foot frame? Basically enclose the wheels and raise the floor up above the top of the wheels. Is that a good or a bad idea?
I ask because, though I'm a woodworker and cabinet maker, I've never done metal work/welding. Not sure I want to acquire yet another set of skills and the tools to go with it. Not sure if I can get a 5 x 8 or 5 x 10 frame for under $500 either. I've been doing a bit of looking both online and on this forum and haven't run into an answer for this - yet.
Any advice would be much appreciated.
Thanks!
Telemorris