Lots of good info here also check on www.rv.net
Your current truck being a mega cab is going to fall short on payload, yes teh diesel has the power. So your best bet might be to look at a bumper pull(non 5th), also watch the garage lengths, most of the under 40' trailers are 12' garage spaces.
My parents have a cyclone 44' trailer and have had good luck with it, they are towing with a GMC dually are still overweight on the gvwr.