Need Exper Advice About Option Combinations

Hi all please advice to me,

For eg: i have one product , phone case i want offer one free standart screen guard(its have already product list), and customer must be select standart protector or premium if selected premium(its have already product list) will be add extra cost and must be add to cart both standart or premium,


If i use option combinations its work only price side. But how can i drop with stock and add show to invoice


Anyone can offer me any solution?

If I understand you correctly, you should set the Inventory setting to Track with options on the product details page. Please check the following article

http://docs.cs-cart.com/4.7.x/user_guide/manage_products/options/inventory_tracking.html

yes i can do that. ithink cart power's Product packages will solve my problem