This sounds like a job for Web Form Builder maybe? I know this will end up being a little more work than necessary since it will entail 2 different media for 1 order between the order itself and an email message, and it's not real viable if this company does major volumes of business and would have a hard time keeping their customer info together but... here's my thoughts on a possible option since the SCC is definitely not going to work for you any other way that I can think of.
Create a form in Web Form Builder, add your flavor choices to this form and have them do their setup that way with either a number of drop down lists where they choose each flavor from the list on X number of dropdowns, 1 dropdown for each choice, or with check boxes to select their flavors. I would suggest the Dropdown lists as they are more controlable than the checkboxes are.
Insert this form using the HTML insertion setup in the Details area of each Pint Group (4 pts, 6 pts, etc.). This email gets sent to the same person that handles the order and they match them up together when the order is recieved from PayPal and you now have choices.
Be sure to have the form return to the same page it is on, so that it returns right to that particular item page so they can now purchase it. Tell them to make their choices first and submit, then to do their purchase so the info flows through more smoothly (going back to a page from PayPal is not as easy as from a form).
Albeit it's not a perfect solution, and has a tendency to get confusing if it's a high volume business, but it's a possible solution that would still allow you to use SCC.
