1. Louvered tail gates besides being ugly have only one function. They allow hitching without dropping the tail gate. When not towing they provide zero security.
2. Brush rock flaps again are b_<< ugly IMHO. They may pososibly help prevent some rocks from hitting the trailer. But how many times are you going to be pulling down a gravel road? I have some custom molded mud flaps that do just fine and dont make my truck look like a semi wannabe.
You should instead consider buying a lockable bed cover for times your not towing, keep the stock tail gate and if your really worried add nice custom molded mud flaps. At least the truck wont look okie that way.