SEO for e-commerce site

SEO and marketing help for our small business e-commerce website. Currently we have a complete PPC campaign so keywords have been determined. We are looking for increased organic placement on the major search engines using white hat techniques only. Black hat or grey hat methods are not acceptable. Absolutely no blacklisted or spam sites of any kind. We want only honest, best practices used as this could potentially be a long term project. Another important aspect of this project is a thorough examination of our site to find any broken links, weak content, keyword placement, anchor text, readable sitemap, etc. Of course our goal is increased traffic and we will monitor closely any increase from our base traffic now. But… we are looking for sustained traffic and placement long term. We are also looking for advice on work we can do in house to increase traffic and placement as well from our end. We are looking for qualified, professional SEO experts with a proven track record that can be verified. When bidding please explain what techniques will be used, how much experience you or your firm has, your plan for generating increased placement, and exactly how milestones are to be achieved and paid. Thank you