There are a couple other companies that put out organic dog food lines.
Blue Buffalo is one of them, they have a new organic line they sell. Petco used to carry the whole Blue Buffalo line, but I no longer live near one so I cannot tell you for certain. (Blue Buffalo isn't one of the top top foods out there, but it is a good food - some dogs just tend to not like the cold pressed vitamin nuggets.)
Natural Balance also makes an organic line, and Petco should carry those as well.
Castor & Pollux also make organic lines, which I believe Petco still carries.
Is there anything in particular that confuses you when it comes to making a food choice? Maybe we can help you out?