Actaully for LOCs, I've only ever seen high end types recommend David Navone LOCs.
http://www.davidnavone.com/adaptor_products.htm
It's what I used to run an amp to my stock unit in my mazda 5 and what I was planning on getting and using in my new civic. I just got the car so I'm trying to figure out where people are wiring the amp to? Are you taking out the dash to get to the back of the HU in order to get the speaker level out?