[Quantity box?] for products_options_values

I am trying to make a build-your-own shelving unit where you can choose the products by different size selves and 2 way, 3 way, 4 way joints.

I would like the customer to be able to input the amount of selves and or joints by product value or maybe by option alone.

Here is a close example as to what I am trying to accomplish:
http://www.giovannettimobili.it/negozio/index.html?lang=it&target=d47.html

But I would like it to add all the inputs into the cart at once.

Anybody have any idea as to how I can achieve this?

What if you put the peices and parts into its own Category? Or is that too complex for your Products?

Ajeh:

What if you put the peices and parts into its own Category? Or is that too complex for your Products?

I thought about that,
But for customers you should have most everything laid out on a platter for them, if you make them have to go back and for to buy items, they will most likely not.