Accountant to work with developer on UK VAT project.

We have a bespoke double-entry accounting system that handles VAT, accounts, annual returns, for UK limited companies, specifically IT contractors. I am looking to migrate the system to use the iXBRL gateway to supply VAT returns electronically. I need to work with an accountant who has experience with this area to come up with a design for a system to handle that. To be clear, I am only looking for accounting advice/consulting specific to VAT returns, and not programming of knowledge and/or of the iXBRL gateway. Ideally you would be a qualified or trainee accountant, with experience completing VAT returns and so would have a good knowledge of scenarios such as zero-rate, non-vat, place of supply, services and products, flat rate etc.