To change the sword model, rename a new sword model to the one found i "meshes/Hacts/CustomBoundSword...". If the model isn't from vanilla skyrim f.ex. a mod add the corresponding textures as well.

Standard model is the nightingale sword. Book can be created at the forge by combining a bound sword spell tome and a clairvoyance spell tome.
You only need one of the versions as they are dependent on the perk tree.

Credits to Seorin creator of SPERG, a great perk overhaul!