You do not representation when you meet with HMRC, they are fair and will see that you are doing all you can to clear your debt with them - and will try and reach a compromise with you to settle the rest in a payment plan,
Just word of warning though, interest will continue to accrue on payments that are late - so be mindful of this
.I used to conduct meetings such as this when with HMRC, and it was about trying to settle the position in a short as time as possible, so you may find that if you can reduce the period of time down from 2 years (although go in and offer this up first) then HMRC will be more willing to play ball.
But offer what you can afford, as you do not want to end up with late payments within the agreed plan which could see HMRC then pursuing for the full amount.
Also by offering direct debit, it shows an intent to comply - which will also work in your favour -(this could even swing the decision to agree to a longer payment plan) as it means that it saves HMRC admin costs and staff time to chase any late payments.
Showing you are willing to sell the property will certainly work in your favour, as HMRC can see a larger one lump sum settlement towards the overall debt - but I do feel that you should be sure of this decision and it could be worth seeking debt advise/financial advise before proceeding.
Let me know if you have any further questions that you feel would be of help to you, but you are clearly making roads in trying to pay off this debt and that's a good thing and that is how HMRC will view this.
If HMRC offer proposals that you are not sure of, then ask them to let you get back in touch after the meeting so you can be sure that you are thinking straight, as I do know that these meetings can feel a little overwhelming and full of worry on the customers part.