Best way to keep products syncronized with inhouse inverntory system

Hi there,

Im developing a website using woocommerce, but the client has an already built inhouse system where they manage all the inventory and sales from their physical stores.

What is the best way to keep both invertories syncronized.

Here is my plan:

1. Everytime a user purchase a product send a request right after payment is confirmed to update stock in the in-house system.

2. Everytime somebody purchases a product in a physical store make the in-house system send a requets to the WooCommerce site to update the stock.

3. In addition to that, configure a wp-cron either at WooCommerce on in the in-house system to sync the products looking for any picture update or other things.

It is a small store (400 products) so I think that should do the job without overloading the servers, but I feel there is a more elegant way of handling it.

So any ideas that may point me in a better direction would be highly appretiated.