Modify Opencart

We need to modify our opencart website. Adding a "al a cart" system that controls the amount of meals/ products that can be added to a cart based on category and selections. below is a example of ordering structure that we nee to create logic for in the opencart system. We need these files to be able to be installed and configurable from the open cart admin side also. So when we install the files to opencart we can manipulate the settings also. this will require some additonal coding and styling for opencart admin as well. please review and reply with "ocdev here" to be considered . We have an order system desired as follows: customer chooses -> (link) "Create your own meal plan"<- customer chooses ->(drop down or icon in category list)"Select Portion Size"<- option 1 oz option 2 oz option 3 oz option 4 oz 3. customer chooses ->(drop down)"Quantity"<- option 10 meals optoin 14 meals option 21 meals Based on the above selction from #3 options we ned to show an a la cart list like "The Popout in smart cart" Here is where some logic begins. if 3. option 10meals then limit the nubmer of items that can be added to cart from the next sections 4. Add meals to your plan.->(the pop up with 3 tab categories)"Breakfast, Luch, Dinner"<- in the tab categories we need to limit the amount of meals that can be selected to be addede to cart based on the number of meals option in #3. logic for #3 option 10 meals. customer selected -->option 10 meals<-- customer can only choose 10 meals from either "breakfast, lunch or Dinner" products in pop up 5 breakfast / 5 lunch or 5 dinner only (no more than two items in the same tab categories can be selected.) logic for #3 option 14 meals. customer selected -->option 14 meals<-- customer can only choose 14 meals from either "breakfast, lucnh or Dinner" products in pop up 7 breakfast / 7 lunch or 7 dinner only (no more than two items in the same tab categories can be selected.) logic for #3 option 21 meals. customer selected -->option 21 meals<-- customer can only choose 21 meals from "breakfast, lucnh or Dinner" products in pop up 7 breakfast & 7 lunch & 7 dinner only (no more than two items in the same tab categories can be selected.)