Looking to outsource our SEO work to save time

We are a small family run Marketing company based in Hildenborough, Tonbridge, Kent, that has been going for over 2 years. We specialise in e-marketing and have recently decided to attract new clients by taking on a Business Development Manager. This has proved extremely successful and we now have so much work that we are looking to save ourselves considerable time by outsourcing all of our SEO work, and form a commercial partnership/alliance with either a specialist company or ideally an individual freelance expert in SEO. Must be UK based and willing to charge by the hour, as we have an extremely varied portfolio of clients, from sole traders to large corporates, who all have varying budgets/monthly retainers with us.