Baby-socks - I don't really know anything about the epidural bit, sorry. But as far as the big baby thing goes, no, a bigger baby does not necessarily mean a harder labour. It will depend a lot on the position of the baby, and whether the weight is in fat, or bone, if you know what I mean. A baby with a big head and broad shoulders is probably going to be a little harder to push out than a chubby, but petite boned, baby. I've also heard it said that a big baby is easier than a small one because a vigorous, strong baby "helps" to deliver itself by straining and stretching against the push of the uterus. I can't say whether that's true or not, but it's something to consider.
All the best!