Shinai measurement and styles

Finally found a small answer to a larger question. Shinai are measured in shaku and sun. A "39" shinai is actually 3.9 shaku, or 3 shaku 9 sun. I also found:

Shaku = 11.930542"
Sun = 1.193054"

Found some more information on styles, but nothing to quench my thirst for knowledge. It seems that Koban style have a oval shaped tsuka (instead of a typical circle shape). Also, dobari style are fatter above the handle. My new question is can you have a koban dobari (dobari koban?) style shinai? This is quite confusing. I've found some decent information on the Kendo-World forms regarding the pros and cons of oval versus circle shaped tsuka. Seems like the only real con has been cost (oval being slightly more expensive) and inability to 'rotate' the slats (which C.J. told us not to do anyway). It might be worth while to get a koban style shinai and see how it feels. Many people commented that ten-o-uchi seemed easier with oval shaped tsuka, except it's more of a squeeze than a twisting squeeze. Very interesting.