My surfmobile #2 was 2001 Dodge Dakota SLT Plus Quad Cab powered by the 4.7 V-8 engine. It was a 2WD version with a limited slip differential. I carried my boards and masts on the bed-mounted VersaRacks made by Tailgater. The bed was secured by an A.R.E. tonneau cover which allowed me to keep my gear locked up and out of the passenger compartment and allowed for extra carrying ability. I had to lenthen the cross bars for the tonneau cover to clear even though the VersaRacks were advertised to work as is. The supplied bars were only 48". Not even close to the 6'6" required.
Inside, the bed was covered with a Line-X spray-in bed liner to protect it from salt water. The bed was also covered by outdoor carpet to reduce the wear on the sail bags from the liner. Above the bed is a shelf that I made out of 3/4" exterior salt treated plywood. It was held off floor of the bed by the wheel tubs and two legs and was also covered with outdoor carpet. I kept my sails on top and my other gear including the booms underneath. I added a battery-powered fluorescent light underneath the lid for late sessions. I hade to support the lid with a carbon strut (can you say broken mast?) if I have a board mounted to the lid due to the extra weight.
I added a set of artificial rain gutters to the tonneau cover so I could attach my Thule racks. This allowed me to carry even more. The tonneau cover supported a lot of weight so I could carry as many as four boards on it.
With this setup I could easily carry four boards on a regular basis.