I guess you know the truck is not rated to plow already,but id do it anyway,the truck is plenty strong. I plow with a 2000,short bed,9 '2" Boss V plow. I say,get a western plow,its lighter,and extremely proven,then you can get an 8. 5 ft wide plow,and only weighs 730 lbs,a 7. 5 is to small for the big Dodge,when its angled,its only 6. 5 wide,barley clears the tire tracks going straightn,as soon as you turn,especially with a long bed,quad cab,the rear tires will be in the snow berm,making a mess. Check out my pictures of my truck . After having the 9'2",I will never own a 7. 5 ft plow again,your dodge will push a 9 ft easily. The wider plow allows you to get close to houses,curbs,and mailboxes without hitting the truck,or hitting mirrors on anything,whichever you choose,get at least an 8. 5 ft. An 8. 5 ft will leave you 6" clearance on each side of the truck,at full angle,the 7. 5 leaves you zero,so you hit the truck,mirrors,or have to leave some snow ,and shovel by hand. here are my pictures of my trucks.
http://www.angelfire.com/ct/construction/johnd.html