I need a cross selling module adding to my OSCommerce site

I would like a contribution adding to my heavily modified OSCommerce site. It needs to be similar to the following one, where I can select from within the admin cross selling products, I would like a product list with check boxes next to them(in the admin site). So when my customers view a specific product, they see my selected products as related products at the bottom of the page. I have seen this described as setting up relationships between products. [login to view URL],5347 In addition to this I need a text box adding to a product, this allows my customers to give there product a name. This feature needs to be selectable, so I should be able to turn this box on or off depending on the product, as only a few of my products need this ability.