Alanek, check out the web page for Invisible Structures, Inc. of Aurora, Colorado. They manufacture several products to utilize in a french drain system. As far as the specific design for your particular application, I suggest that you contact a local engineer, one who is familiar with drainage system design, to design a system which will be adequate to fulfill your needs, and satisfy the various site constraints existing on your site. Inform the engineer of the Invisible Structures products, and insist that he or she include them in the design. The Invisible Sructures web page address is:
http:/www.invisiblestructures.com
Good luck in your quest for a successful drainage system. JWA