Rich,
1. Do not be confused by Make preferences. Sniff around for the best 'deal' on a SRW one-ton. If you are really getting a Large TC, by all means head in the direction of a duallie. Too many of my friends have pushed the envelope of what a SRW capacity can be and are now, and have regretted it.
2. Convince a long-time, TC wielding friend to look at different TC's with you. Have a wide circle of geographic area that you will even look at a TC, say 500 to 1000 miles. Remember that a TC really breaks down into 'systems', like electrical, plumbing, fit and finish, layout, built-in comfort, and size. Does the water pump make a lot of noise? Not good. Do any of the tanks leak? Is it air tight? Does it leak rainwater? Does the roof have a dip in it?
Develop an idea of what you cannot do without.
3. My personal conviction, since we don't suffer from claustrophobia, is to aim at the smallest hardside that will work for you. You just learn to take less stuff along. But, only you can decide where the line is.
The bottom line is, you want to make good decisions the first time out, which is, dare I say, an art form. Me? No art here, I just got lucky the first time out. I knew nothing. Some say that is still the case.
regards, as always, jefe
