What I need to accomplish may be impossible.

We will be selling a kit that combines 2 standard pieces and either 1 or 2 pieces that are chosen by the customer. I know that I can create a matrix item to allow the customer to mix and match the optional pieces (each option has about 10 items to choose from).

Illustration:  If this were a food gift basket, the customer gets standard 1 danish and 1 muffin (both individually lot numbered depending on when they were made). Now they can choose the optional items - they can choose either 2 pieces (one from each list) or 1 piece (just one item from either list). Let's say the options are Vanilla wafers with a choice or different fillings for item 1 and Chocolate wafers with the same 5 choices of fillings for item 2. All 10 items are individually lot numbered as to when they were made.