Both my babies were back to back. The reason why the labours are often long (as mine were) is that the head does not make a good contact with the cervix which can lead to irregular contractions. I had an epidural in the end with both of mine, but only after about 16 hours of contractions (so the contractions themselves are bearable) but I was becoming tired after that length of time.
Both babies were born vaginally, no1 with ventouse and number 2 unassisted. The epidural is quite handy as it allows for time for the baby to turn, which happens usually during or after transition. WIthout the epidural I think the urge to push would be quite hard to ignore. As it was with the epidural I got a nice 1 hour long rest before starting to push.
Tearing was quite bad, but that was because they were big babies, both 9lbs, 8oz.
I really think that you should not frighten yourself about this. As with all childbirth experiences, you will get through this. How you do that very much depends on your own experiences and preferences. I really don't think that any 2 woman experience exactly the same labour, even with quite similar circumstances.
I wish you the best of luck, and remember the way to get the birth you want is to be well informed and build a good relationship with your midwife. Oh and if at all possible avoid coming into contact with doctors, once they get involved everything seems to be much more intervetionist!