Up sells module for osCommerce 2.2

I have an online shop, osCommerce 2.2 platform and I need an up sells module that works like this: In admin panel I must have the option for all types of categories (category, subcategory, sub sub category etc) to assign 0, 1 or more products to each category that will show up to the customer during the check-out process. Example: If I have 3 categories named category 1, category 2 and category 3 I will make the followings assignments: Category 1: products A, B and C Category 2: products F and M Category 3: product X If a customer buys products from my shop and the products that he is ordering are part of category 1, then on the checkout payment page ([obscured][login to view URL]), below the "Observations" field, the up sells module must appear and the customer must see only the products A, B and C. If the customer is buying products from categories 1 and 3 the up sells module must show 4 products: A, B, C and X and so on. The following rules must be followed: 1. The products that show up in the up sells module must have a direct link to the normal product's page. 2. If a product that should appear in the up sells module is with stock zero (visible on site but the customer can't order it), then that product with stock zero must never appear in the up sells module. 3. The up sells module's title must be "Pe baza produselor comandate, consideram ca v-ar putea interesa si urmatoarele produse:" 4. The up sells module must have 3 products/line. The only line with less then 3 products will be the last line. 5. No products limit for the up sells module. 6. No limit for the products assigned to the categories. 7. In the admin panel, at assigning products to categories, I must be able either to search a product by category, either by manufacturer. 8. If a product is not present anymore on the website it must not be vesible in the up sells module. 9. The design of the up sells module must be exactly like the default design that I have on the website right now, exactly how the X-Sells modules appears. Please note that this job must be compatible with X-sells module that I have right now installed and working (which I use as "Similar products" module). No conflicts between this 2 modules must appear!