Hi there and a late night welcome to the forum!
An IVA, if you decide to proceed down that route, will be based upon the amount you can afford to pay each month and the level of assets you own. So you should not get carried away by the spin of writing off 75% of your debt, but believe that you can pay as much as you can afford over a set time period.
If you are a property owner, you will not be able to avoid the equity release provision as this is now standard procedure, so maybe you ought to look to other options - perhaps a DMP if you are looking for a more flexible approach. Do rememeber that a DMP will not give you the level of legal protection afforded under an IVA, or guarantee that creditors will stop charging interest, so you may end up paying more for a lot longer under that process.
Regards, Melanie Giles, Insolvency Practitioner