I like Edmund. I'm not a huge fan of Esmond at all.There's another nickname for Edmund - Ned. Not sure if that changes your mind, but it's a different sound.
Ned is okay, but I would still fear he would someday decide he liked Ed, and that would make me cringe. I almost never want to use a nn because I feel the full name is always better. Edmund is the only name that I refuse to use due to the nn because I simply cannot stand it.