unfortuately there are so little Ob's who are prepared to just let nature take its course with twins. There are so many variables with twins, and so many things that can go wrong- even more so with ID's..
I really wanted a natural birth, but chose a hospital (FP) that had a level 3 nursery in case things went wrong. i knew that by going there that my chances of having a natural twin birth were pretty low as my OB was more inclined to do a c-sec, unless twin 1 was head down.
My decision to forgo a natural birth and go to FP saved my babies lives.

What I am trying to say is that although it would be great to have the best of both worlds for both mum and babies - with twins its that bit much trickier, and it is very hard to get a balance between the two ( or 3 lo)
good luck with your choices, and whatever you decide -stick to your guns, as you alone will know what is best for you and your babies!!