Kate - if you don't go for the homebirth perhaps you would like to consider a midwife-led birthing centre attached to a public hospital? I had my very empowering second birth at one and took my doula with me. It was a fantastic experience to be surrounded by wise and gentle women and the great home-like facilities they had there.
Just thought I'd mention it. That way if all goes well (as it should!) you may feel more comfortable about a homebirth 2nd time around.
Best wishes whatever you decide!