Here is what you've all been wanting. An expansion for FS 2004 that allows you to earn ranks, manage your own airline, fly real routes with correct liveries. Check it out. Only about $40 but it's professional.
I've really been looking into getting it. It sounds a little like fspassengers, however I like it more, mainly because I go for the pilots actual career, not every individual flight. I think it should be a good buy.