I have heard that in most cases it does not matter who files first. In my case my attorney wanted to file first in an effort to get an upper hand on my situation and control the tempo. So far in my case I have to say it has worked for both custody and property.
I would think that most of your issues will eventually be brought up in court if it can't be mediated civilly. Thats the time when you need to be firm in your requests and have the backing to go with it. I also don't think it will matter that she makes more and you have been more of a stay at home dad. You should still get a say in the custody and any financial support.