Customer Area Stock Management

Hello,

I have trawled the forum this morning trying to find a similar request but unfortunately I haven't found any info/extensions that meet my requirements.

How I Work
I sell on account. Customer do not pay directly on my website. They make an order then I send it and invoice them for 30 days after.

What I Need
I need something built within the customer login area so the customer can adjust how much stock they currently have. For example if the customer has quantities like this:
Product 1: 2 in stock
Product 2: 2 in stock
Product 3: 0 in stock
Product 4: 1 in stock.

If the customer can login and adjust how much they currently have in their stockrooms. I have an agreement with them that they will have 2 of everything in stock at all times. So as they use the products they login and change how much they have left, I can then see that every week on a Friday I have to 'top them up'. So in this case I would need to send out Product 3 (x2) and Product 4 (x1). It would be a nice touch to have e-mail notifications for when a customer logs in and updates the quantities of stock they have.

Any ideas or potential mods that fit my requirements would be appreciated.

Thank You

Kind Regards

Matt