VIPER131'S RIDE

How do you like having a rack on top of the above cab shell? I'm looking to buy a shell, I want it to be above cab for more head room as I plan to build it out for camping out of it, but I also need a rack for my 12.6" SUP board. I'm nervous about the stability of the long fiberglass board sticking out past the shell/above the cab when it's on the rack. Any info/advice?