Not being an expert on these things but my brief research into ILR would suggest that that quite likely demonstrate the permanence necessary for domicile.
http://www.globalvisas.com/uk_immigration/
indefinite_leave_to_remain.html
If ILR has now been granted then Bankruptcy or IVA should now be open to you. However, get the advice on your job before you take any action at all on the basis that you can't be sacked for merely enquiring about something.
I would agree with Melanie that if you enter into an IVA that incorporates overtime, unless that overtime comes with a cast-iron guarantee then there is a high risk of failure.
Forgive me if you said this elsewhere but how much do you owe in total?