I don't think that makes you terrible at all. I think if you make an informed decision than you shouldn't feel guilty or bad about it. If what you are really looking for is someone to talk you into a natural birth I am sure there are plenty of links and videos and statistics that mamas can direct you to.
I have had a few doulas say that 7cm is a pretty magic number and if you can hold off until then the risks are reduced (no clue if there is any data to back that up), but maybe thats something to look into to help ease your mind?
I will say that you should never count on the labor/birth going a certain way (as I am sure you know). I was all for the epidural with DS. Instead I had problems starting about a half an hour after I got it. It started out spotty and then made my blood pressure crash. Around 7cm they had to turn it off. I was not at all prepared to mentally handle the pain. So my focus with this pregnancy was to prepare for a med free birth just in case.
Meg, Momma to Joey (Feb 2010)