Krissie,
Congrats on your pregnancy. You are asking some really relevant questions and I hope your new gynae is supportive of you wanting a VBAC.
Practically your chances should be good. If this pregnancy has been good and you are in good health and watching yourself so that the pre-eclampsia isn't an issue then you should be given a trial of labour.
I am not going to pretend otherwise but there is a risk with all pregnancies not just a VBAC so your chances are the same pretty much, the important thing is to have a caregiver that is comfortable doing VBAC irths. Not all doctors are okay with it as they have had little or no experience whereas those who had done their fair share are more willing to allow a TOL as they know from a practical point that it works for the most part.
There are times when a VBAC doesn't work but most women are happy to have at least tried and this in itself can be very healing too.
Midwives on the otherhand have much more experience with VBAC's and your chances of a successful VBAC increase dramatically by using a private midwife versus a doctor alone.
Where are you based and perhaps we can recommend some more options for you to ponder on?
Love and light
Lia
xxx