SEO Expert needed

I am seeking an expert to help improve the number of visitors and google page rankings on 2 websites , with the ultimate goal of increasing sales so I am looking for quality visitors not just an increase in quantity. Both sites have google analytics installed so full details can be provided. I would also like to see recommendations on how social media could have an affect and how and where external back links can also help.
I have a small budget and am looking for a longer term contract with the successful freelancer, to be paid on a monthly basis as I see this as an ongoing piece of work that is required. If this is unachievable then please let me know what you can do for me at what price.
I would like to start work immediately on this so would prefer proposals by Thursday 20th October so I can review and appoint on Friday 21st October.