The Tao of Jeet Kune Do is very appropriate to fencing -- when Bruce wrote this (actually, it is a compilation of Bruce's notes after his death by his students; it was in the works but not published until after his death), he took much from fencing (from Castello's book; long out of print) he found this as an augmentation and a good explanation of principles to his training in Wing Chun, which between the two is the foundation of Jeet Kune Do (which isn't really a martial art onto itself, but rather a philospophy).

Other good books for Zen include Samuraui Zen, Art of War and Letters from the Swordmaster (can't remember the title exactly).