adding custom options in magento

The is in magento 1.4 community edition It involves customization of the custom options in magento I have 2 products as follows 1st product 1st dropdown price $10.00 2nd dropdown price $10.00 if the user selects any one of the dropdowns then the price added to cart would be $10.00 if the user selects both the dropdowns then the price added to cart would be $17.00 (a disount of $3.00) also when the user selects an item in the dropdown then the selected item image should be displayed on the page 2nd product Similar to the above instead of dropdowns there will be checkboxes 1st checkbox option price $5.00 on selection of this option the user should be allowed to input information in some fields 2nd checkbox option price $8.00 on tickmark of this option the user should be allowed to input information in some fields I have a large number of products so doing the above via configuraable / attributes is not an accepted solution