OSCommerce Add-ons to existing website repost

Our client has an oscommerce website that sells adult toys. We need new features added. Coders may use oscommerce contributions as long as they work and do not break the existing website. Many files have already been updated and customized, so all code changes need to be made the the existing files on the website. **Do not just replace files!!!** Here is a list of the features we need added: 1) Wish List 2) Gift Certificates (needs to be automated) a) website needs to keep track of how much money is left on the certificate (this can be a code that is entered at checkout) 3) Ability for customers to purchase a "% discount code" a) This discount code will need to expire after 1 year and should only be usable by the purchaser's account. 4) General % discount codes that can be created by my client. a) this is different than the other discount code. This one needs to change the discount according to the purchase price b) $0-$199 = 20% discount c) $200-$300 = 30% discount d) $301-$500 = 35% discount e) $500 and above = 40% discount 5) Take out the “+/- Dollar amount?? from the dropdown menu for the products attributes. Ex: <[login to view URL]> 6) When looking at a category, the heading “Let's See What We Have Here?? needs to be replaced with the heading of that category. Ex: <[login to view URL]> The heading should be “Body Toppings And Art