I would try to get more down-travel. Bump stops can cause more problems than they're worth, it's alright if the chassis hits the ground.
I've never built a pair of Kyosho shocks, so I don't know what pistons to run. I'd try 40 or 50 wt. oil just for kicks and go from there.
jbrow - My truck has enough drag brake to start slowing the car down once I let off the throttle. At full brake, I have enough dialed into the car to completely lock up the rear tires. I tend to really only use my brakes in traffic and in the air, and slow the car down by throwing it into the corner, Steve Kinser style
