SEO PPC project

We wish to develop a larger presence online through our website www.ticketpro.com. We have been using Google Adwords and Overture and though this has been very good for increase exposure we would not like to get a much better 'natural' ranking in the main search engines through directory listings, links, etc. We would also be open to advise on modfiying content on our website to help in this endeavour. We are open to any black or white hat procedures to achive this and recgonise that it will take time for any seo actions to be reflected in higher rankings. We are looking to establish an ongoing relataionship with a SEO and PPC expert who would continue to enhance or rankings on a monthly basis. Our monthly budget is $50 but this could be increased if there is a case made for it. The winning bidder should be able to demonstrate an overview of the intened approach and the expected results. Other reference sites would also be desirable.