An IVA is a great way of protecting your home and equity as you continue to pay your mortgage throughout.
We had 200k debt and a lot more equity than you and although I believe there are more ways of re-mortgaging at the end now we could not and our mortgage was paid off shortly after we finished.
IVA completed with StepChange.
Last payment Sept 2016 CC Oct 2016
Yes it is possible, especially as the estimated IVA outcome is compared to the estimated Bankruptcy outcome and the Bankruptcy costs are very high compared to IVAs so can mean creditors get the same or more money back in an IVA.
It's definitely an option. Whether it's the best option will depend on other things but one of the experts here will be able to give you some specific advice if you contact them. The most important thing is taking control so you have already taken the first step. Good luck with it.