Depending on the year of your Durango, it could be very different than a truck. My 2002 Durango is much lower than a 2012 or newer Ram truck. My Dad had a 2005 Durango that was higher than mine (enough that he couldn't get into his after knee replacement, but could get into mine), but was still significantly lower than his 2012 Ram 3500 truck. Again, go test drive some and get a real idea of any difference.
I agree with stetwood regarding size. How much space you need has a direct bearing on your personal particulars. Many people will tell you to go bigger than you think you need, but they are usually fulltimers with a different set of needs than a weekend camper; and visa versa.