In a general sense (and especially as applied to your question), morality is highly personal and subjective. And not only that, but it changes all the time. What you think is immoral today ("charing customers for customer service") will inevitably shift as your situation and personal beliefs change.
If you ask Richard Stallman, non-free software is "a crime against humanity." Heck, even associating with propietry vendors is imoral and, those who do, are traitors to the movement. Communitists say the same thing about the profit. My point being that, no matter what you do, someone will tell you that you're being immoral.
Instead of figuring out where your (or anyone else's) "moral limits" are, you need to be prepared and feel confident that you can handle those "on the edge" descisions. Situations will come up that will break your moral rules, and sometimes that's okay: you've been wrong about other things before, and it's possible that your rule was wrong.
Most importantly, don't publicize your moral limits. It offers almost no benefit because basically no one really cares that you "are always green" or "will never do business with military contractors". Worse, it pigeonholes you into a (probably stupid) position that you will want to get out of.
Remember that "Straight Edge" thing that kids were doing back in the early 90's? It was like a lifetime commitment to no drinking, no sex, no meat, and other stupid counter-culture crap. Some teens were so into Straight Edge that they got big-ass tattoos on their arms and legs. Now just think of how embarassing that has to be today, as an adult, while they're out enjoying a steak and a glass of wine with some friends.
And if you feel the need to absolutely positively tell everyone how moral you are, then use completely vague and meaningless statements like "do no evil". It'll reel in the "ooh wow, they're a moral company" suckers and not prevent you from making tough decisions.