I want to try to get out of my marriage without her knowing what happened but fear that once I start a relashionship with this woman it will be known.
Oh geez, grow a pair. You had the cahones to cheat on your wife with your neighor, have them to own up and face the music.
If you want to try to get out of your marriage without owning up to what you are, fine. But don't sit around for years trying to figure out a way to save face while wasting more of your wife's precious time left on this planet.
I want to know if it is worth taking the chance so I don't completely destroy our families by having this come out.
What makes you think divorcing for any other reason than you F'd around will make things any better?
If you don't love your wife, quit wasting her time. Tell her you don't love her anymore. Problem is, that isn't going to be good enough and if she is smart, she'll smell a rat.
So get on with divorcing your wife, setting her free from you, so she can move on with her life and hopefully find someone that cares for her. Your need to save face shouldn't be her problem.
I know I will get a lot of people telling me how horrible I am. Yes you are right, I am. Please try to help me figure out though how to best handle this situation without it going so horribly wrong for the innocent parties.
This isn't about sparing them, its about you trying to save yourself from the shame of what you did. Face your consequences and set your wife free.