Focusing first on the shape and profile, the "Flow2" kit compliments both the rider and the motorcycle simultaneously. The kit comes complete with bond-on gas tank halves and matching side covers that look like one piece. The side covers are direct replacements and mounts in like factory-made. This setup works with all bag stretches from 4" to 8". You do not need to make any custom seat, as this kit will work with your original one as well.
For Roadking models you will need to drill filler and fuel gauge holes after gluing covers on the tank.