Hello,
If you are very keen to have a natural birth and would like someone to hold your hand in making your decision, I'd highly recommend the birth buddy scheme called Tell Me a Good Birth Story that was been set up by my antenatal yoga teacher, who is also a doula. She does great work in helping women achieve the kind of births they want. You can find out more on her website at
http://tellmeagoodbirthstory.com or for more stories check out the blog at
http://tellmeagoodbirthstory.blogspot.co.uk/ where you can read the real-life experiences of women who have had VBACs. The birth buddy scheme will match you with someone locally who has been in the same situation as you, and you can email, chat on the phone or meet up - it's an amazing way to get support and the whole concept puts a brilliantly positive spin on birth, which you don't often get from the NHS!
Good luck with your decision, and your birth, and for getting your head around having two little ones. As someone else said, going from one to two doesn't seem quite as bad as you fear, since you've already made the big transition. That said, if you don't have family nearby to help and can afford a bit of extra help, go for it! 8 months in, I have just got an amazing girl to come and help from 5-7pm and it's a life-saver. It's supposed to be a short-term thing... we'll see!
Wishing you all the best!