Wanted: Timed product in Cart checkout

Hi Guys,

I make and sell unique items in my Opencart store and have the problem of 2 or 3 customers checking out at the same time with the one item. This creates 2 or 3 sales of the single item and lots of trouble for me.
Opencart is allowing this because it waits on the payment confirmation to come from the payment processor before taking the item out of inventory. This is too long when 3 people are checking out all at once and allows the item to be sold 2 or 3 times.

I need an extension, or module to control the customer cart so when the first customer puts the item in their cart it is taken out of inventory for a certain amount of time (say 15 minutes), then returned to inventory if they do not checkout in that time.

Any help is appreciated.
Thanks

If you're using an extension module for inventory handling already, I would suggest contacting the author of the contribution to add the features you've described.