Learning Classical is a pain in the butt...any seating recommendations?

I picked up a guitar stool from Guitar Center and quickly found it to be way too high for the classical posture. I borrowed my brothers regular old drum throne, which is a much better height, and am going between a support and a footstool. With both support, footstool, and support but with my feet on the guitar case (seems to create a more stable platform) my butt really starts to hurt and feel numb after maybe 15-20 minutes.

What do you sit on, and how is the comfort?