need OsCommerce site modification and SEO

This is the second project I post. The programmer I work with for first project is not good and the problem was still not solved. So I prefer programmer with some feedbacks and proved experience. Here is the help I need in first project but didn't get resolved. 1. I need to have minimum order fee working. 2. There is a bug in the paypal express checkout page. If buyer select paypal as shipping method, their address is not included in the confirmation email. Also, if they select "Change Address" button in checkout_shipping.php., it will pull up all address info of history buyers. This is not right. Other than the above two issue, here about what I need for this project: I am running an online store built on OsCommerce, parked at lunarpages.com. The site is related with toys (physical toys only) for mature audience. I need some help to install some contributions. 1. Contributions related with improving search option on store. 2. Contributions related with SEO. If you don't have any feedback, please PM me with your suggestion on what type of contribution I should install "search" and "seo". This might prove that you really have experience but just new to getafreelancer.com. I select the very small budget option. If you think your work deserves more, just give me the bid. OK. Thank you for your time.