Everyone travels differently. A good rule for full-timers is 1500/person, now that's not all in clothes and shoes!! That includes everything you'll pack - dishes, pots, BBQ, linens, books, computer, printer, bathroom stuff, tools, ladder, hobby equipments (fishing, sewing, etc.) It really adds up.
It's very advisable after you've packed it up to get it weighed. You'll be surprised. Overweight vehicles are dangerous and will blow tires.
Surely you can find a suitable floorplan in many manufacturer's lines with good carrying capacity. Also, a more top line generally has better capacity - better axles and bigger tires. Sometimes it's necessary to shop out of your immediate area. First look online for comparisons and then find a dealer. Keep in mind that dealers don't usually carry every model so you may not even see in person what you want. It's a big job. :) Good luck!
