I can think of one rig that will fill all of your needs, and then some
-size for extra people
-tough
-good pulling power
-mileage
-reliability
My reccomendation is a Ford, crew cab (4-door), 4WD, Powerstroke diesel. Mine will tow my sled AND haul my 11' camper with power to spare (it has a std. transmission cooler), when I'm not carrying a load it gets 20mph, engine has a 100,000 mile warrantee, the transmission is made by Cat and seems indestructable. The F-350 short box has a good turning radius (better than the old F-250). With the 4-door crew cab you can hold five adults in comfort. Mine has 70k on it with no problems, friends have 100k plus on theirs with great results also.