I just used this brand u-pol $100 for 4 qts / cataylst and the gun to shoot it. It was easy to mix and spray...low psi and very little overspray. You could get away with a 6" paper taped edge on the side of the bed. There are many brand choices and place to buy from so look around. Some tint/alarm detail shops many do the bed liner as a service that is covered for the life that you own it..meaning from year to year you could get it touched up or redone at not cost. diy is likley the cheaper route...prep is key...power wash it and do a good wipe with prep sol or some other wax/grease remover...a few times...then blow it out and shoot the bed liner.