Check out Boure' ( http://www.boure.com/index.html ) . Their top of the line models have thin chamois. They also have a page on the site detailing the chamois construction. Call, and Boure' himself will gladly discuss the issue with you.

The quality is first class and if you don't like it after several rides, you get your $'s back. I've got two bibs from the guy. I can't stand tightness about the right knee and his articulated knee area works very well for my problem.

They are not cheap, but they do go on sale.

Al