Hey, birth is not automatic!! Believe me!! That's why it's called 'labour'. You have to actually do most of the work!! It came as a great shock to me, this!!
I think you have to wait to see how you feel in labour, really, but don't overestimate a) the effectiveness of an epidural and b) the increased recovery time it might bring with it. That's probably why people are urging caution.
It all depends on the position and size of the baby, and how insane with pain you are feeling. I had one epidural followed by two water births, all with very skilled midwives. Funnily enough I found the birth with the epidural hurt MORE because it took longer and crowning hurt more. I had 2nd degree tears that time as well - it was such a mess the registrar had to be brought down to stitch up my bits. I decided to try doing without for the second one - I practised using a Tens machine for the 3 weeks before the birth (they work best if your body knows what to expect, I found), then took it off when the action was hotting up and I got into the water pool (electrocution is obviously not an option!) The birth was easier that time, even though the baby was, 8lbs, 1lb heavier than the last one. Hardly anything that could be called a tear - just a little graze. The third time I had a 9lb baby who came out in the 'superman' position with one hand by his head, and I had to push for England to get him out, but it was still better than the epidural birth had been, and again I only really had a little graze. For my fourth one I'm doing the home water birth thing again and hoping for the best.
Regarding pain relief, I am no super-natural-earth-mother kind of person, but I think on balance that if you can get into the zone mentally in the first stage, it's really a lot easier to bear the pain, but simply the act of travelling to hospital can destroy any vestige of Zen calmness you manage to muster up, which is one of the reasons I am happier at home. On the other hand, second stage is never nice, and if they ever invent something to stop the pain of crowning I will be first in the queue, believe me. Similarly if this baby is much bigger than the last one, I shall definitely be investigating caesarians!!
See how you get on, anyway, and bless modern science for the lovely drugs if you lose your grip on the pain and feel you need them. But try to have a bit of confidence in natural processes as well, because you get over the birth a bit quicker if this all works in your favour.