Do the search and you will find all the info, debates, and links you want.

A quick comparison...

Rancho 9000s are adjustable, but only for bump or rebound (don't recall which).

Bilsteins B46-1738/1739's provide a near-stock ride and have a lifetime warranty.

Both can be found for reasonable prices. I got my Bils here: http://www.shox.com/