Deduct different quantity pack according to different combination

[ingrossoerisparmio]

Hi,

i use many time a product pack function for to create a kit of "t-shirt" and deduct all quantity of pack but i have a problem when i have 2 combination of product pack through which i want deduct 2 different pack.

Esample:

I have 1 product pack called "Clothes" with 2 combinations:
combination 1: 5 t-shirt 
combination 2: 20 t-shirt

In the product pack i can only set to deduct 5 or 20 for all combination.
I cannot choose combination 1, deduct 5; combination 2, deduct 20.

Can you suggest a change to get this? Or can you suggest me a module?

 

Thanks in advanced.