HMRC are open to the use of an IVA to settle debts, but can sometimes add their own conditions. It will depend on all of your various circumstances and they will look at the options, just like any other creditor. Much will depend on how the figures pan out and the amount of any equity you might have in your home or other assets.
I would suggest a chat with a couple of IVA providers to explore your options in more detail.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014 http://foggy.blogs.iva.co.uk