If you have a catalog from the Kiyota Company, there is a page showing all the bokken/bokuto that they offer, along with a listing of names by style. I also found this website that has some good descriptions + pictures.
http://bokkenshop.com/eng/style.html
As someone who is also training in Kendo and Iai, I have several different ones, and this has been the easiest way to describe which bokken I need... Is it the Jikishinkage-ryu, Itto-ryu, Yagyu-ryu?
At least that's easiest for me....