Website On Page SEO required urgently.

I have a 6 year old website ([login to view URL]) with many backlinks that has recently been hit by the penguin update, I think. I have employed somebody to do an audit, however the results he came back with are a bit above me and I don't have the time to learn SEO and action the findings. What I am looking for is for somebody to go through the "pages" of my website and perform the On Page SEO to regain my ranking, stuff like sorting out the H1 headers and keyword density, descriptions etc. Previously I ranked #2 for TV Wall Mounting, now I am on page 6. What is also frustrating is that my colleagues, in a different part of the UK are now ranking number 1 with a much younger site. I am looking for someone with expert knowledge in Wordpress and the SEO techniques to regain my ranking. I beleive I have enough quality backlinks to make this possible. I am not after a link building contract so please dont bid for that, I want the successful candidate to tell me in English what is wrong and what they plan to do, before they do it. I am looking for somebody that I can trust with my website so references would be preferable. The website is an Organic Themes website, but has been modified so I would like you to be very confident about what you are doing. I would prefer somebody in the UK to do this so I can comunicate with them easily.