If an item sells pull inventory from different sku

I have reached out to shopify support for solutions but no luck, hope someone here can chime in with a solution.

We use POS GO from shopify.

We buy truck loads of inventory and on a truck there is 900+ different items, sometimes there are UPC on items but most of the times there are none. Below is an example of what we are trying to do to streamline our process.

  1. I have a truck called W1234 which has 973 items. All 973 are different.

  2. I create W1234 item for POS GO which is sellable only on POS GO.

  3. I take the x out of 973 items and I create them in shopify and they won’t be available on POS GO but they will be available for sale on sales channels like amazon, ebay, walmart fb, etc.

See example below.

  1. I created 13" Gold Illuminated Glitter Candle With Pedestal item which is from the W1234 truck and I only have 1 quantity of that item.

  2. When I sell 13" Gold Illuminated Glitter Candle With Pedestal on any sales channel (POS GO, FB, IG, eBay, Walmart etc) it should set item as out of stock and it should deduct from the W1234 truck.

What I need is to be able to list items for sale online and use W1234 inventory. Right now all my items have the same barcode because of POS GO (I want to the limit amount of items on POS GO (hand held) since we get 900+ items a week), and I don’t have the ability to create xyz different barcodes.

Thanks in advance.