Perhaps I can answer in place of Ian as he is quite busy this week.
From memory you have appointed a firm in Newport to represent you, who I know well as my practice is based in Cardiff. I am not sure why your proposal is deemed to be "interesting", as if you are self-employed an IVA is an ideal solution for you as an alternative to bankruptcy.
The term "consumer" IVA does not relate to the type of debts you have, but is usually used to refer to non-traders. These days, many sole traders use personal credit cards as a method of funding their businesses, but this does not made them a "consumer" type IVA, which generally relates to employed people with credit card and personal loan debt.
You will need to include debts you owe to suppliers, as all creditors must be included in the IVA, and the fact that you are a trader makes no difference to TiX who are a creditor voting representative who vote on behalf of creditors. I am not sure I understand the issues you are raising here - is your IP saying that they feel your case is problematic? It seems fairly straightforward from where I am sitting!
Regards, Melanie Giles, Insolvency Practitioner