So when I went through this process myself I was told there are two different types of lawyers. Really "nasty ones" that will fight to the end for what you want, or "smart ones." I was given the advice to go with a smart lawyer... i.e. when you are dealing with child custody things it is best to try to be agreeable, take the higher road, etc etc. I used J.D. Hartung of Hartung and Schroeder and felt like he represented me well and took into account my kids needs well, and tried to avoid unnecessary costs or dragging things into court etc. He personally has kids and was divorced himself so understood it personally and professionally. He's not the low cost option though.
However depending on your situation, the nasty road may be needed as well, which would be a different recommendation altogether.
And yeah you'll find differences in cost per hour across the board as well.
Good Luck, the process sucks. Remember to put your kids needs first above anything personal you may be feeling.