I have three kids also, get the Mega cab!!! The room difference isn't even close. For one the crew cab don't even have a full size seat and the middle seat is even smaller. I tow a 36' 5er with a slider hitch and I never used the slider in 7 years and over a 100,000 miles with the trailer. I have a SRW now but I am real close to pulling the trigger on a duelly. Get the 3500 ram and you won't have any problem with that trailer. the 13 and 14's have a new frame and the GVWR went up. According to the brochure I'm looking at right now. a 2014 4x4 mega with 6.7, aisin trans and 3.73 gears can tow 23,320, the GCWR of 32,000. People will disagree but that's what is in the book.
