I have had 2 fast(and i mean fast)drug free vaginal births.
DD was induced at 41+3, 50min labour
DS I wanted to go as natural as possible, so i hung out 3 weeks over due(yes I am crazy) and I was only in active labour for 45mins.
VERY do-able to have them as natural as possible. I believe it is as much mind power as it is physical strength.
goodluck with your up coming birth and I truely hope you get the dream birth that is right for YOU!