SEO Research - Long tail search terms

We're a UK based mortgage brokerage (www.themortgagehut.co.uk) and we're looking for someone to complete a full audit of mortgage search terms.

We want to have a list of search terms, ideally easier ones to rank for so that we can write relevant content and generate leads off the back of it.

So we need someone on an on going basis, first to do a full audit and come up with a comprehensive search list, relevant to industry and complete with typical search volumes.

We would then want a monthly audit to keep up to date.

Please price for initial work first, then we can agree on a monthly retainer.

Your proposal should detail experience and how you plan to achieve these goals.

Thank you.

Chris