Hi,
HikaSerial is compatible with HikaShop variants.
You can create a main product, without pack and create two variants. Each variant would have a specific and different pack (and quantity).
So the customer could choose his pack by changing the variant.
After that, the serial generator could read the order content and access to some custom fields.
Using the custom fields values, it could generate more or less serials which would be assign to the order.
It requires to implement a custom serial generator plugin but it could do whatever you want.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.