I TOTALLY know how you feel! I was probably on my 15th color combo for my wedding when my save the date person forced me to commit this week! I decided on green and pink, but promised myself that I would be flexible on the shades, depending on what it was going on (ie, flowers, programs, ribbons, etc)
I can't imagine its easy to find the identical shade of peach you need for everything. Maybe you could incorporate different shades of peach, which would give you some flexibility. I might be colorblind, but is coral an option? I think you are going to drive yourself crazy if you try to make everything match perfectly!