Hi. If you go BR you will risk losing the house and the car, as well as what you have paid in so far. It is possible that you will also be required to make monthly payments, at a similar level to those you make now, for three years, so, time-wise, you will be no better off.
To fail the IVA you just need to stop making payments, or ask the IP to terminate. You will need a notice of termination to enter BR.
You will also need court fees of £750 each up front.
Having come this far, I would not advise it, especially as your current feelings will pass and you might regret it later on.
Which firm are you with ?
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014