Change stock number on multiple products at once

[Funtasy]

Hello

I'm using joomla 3.4.8 and virtuemart 3.0.12.

I sell products as a general webshop but I also have a products wich combines like 10-15 other products into one.
This is to give the costumers an all-in option.

Now my question was if I was able to just have the normal stock numbers on the articles and when a costumer buys the all-in product, all the other products have their stock reduced?
But also that if the stock number on the general products are to low, that they can't order the all-in option?

Is that possible? If yes, how?

[GJC Web Design]

Well .. have you tried this setup and tested what happens?

[Funtasy]

Well

I tried two things so far not none covers everything I want and makes it user friendly.

First I tried to make a normal product with multible child products. The main product was the general option for the parents and the multible child products were the articles for each child. (http://www.funtasy.be/nl/feestartikelen/all-in-pakketten/voetbalfeest)
But in this setup, I had no control over a stock as I have another products were parents can buy a la carte. These products has the stock numbers.

Second I tried using product builder (http://www.funtasy.be/nl/feestartikelen/all-in-pakketten/boerderijfeest).
This makes a good start to build my main article but not for the products each child.
I have 10 products that the children get. The parents has to change the number for each of the 10 products. Thats not user friendly.

I need something were I have my basic (with stock) and an option were the parents enter the number of children once and that all the other products gets updated in the stock.

I hope you understand what I want and I hope some one is able to assist me in setting this up or showing me a component.