Accepting payment for a product manually when it's out of stock

[Aaronzw]

Hi, I'm trying to find a solution to my problem:

• My store is launching (accepting orders) in 11 days
• It's currently live (www.waggysdog.com)
• I've set all products to out of stock so that people can see them and used the Pre-Order Bear app to replace the 'add to cart button' with an "insert your email to get notified button" to collect emails - see here: https://waggysdog.com/products/citrus-burst-natural-organic-dog-shampoo 
• I'm gifting Brand Reps some products and want to record this order within shopify and collect a delivery fee only (product is gifted free)
• I can't seem to do this with my current setup as Pre-Order Bear app only works when the product is set to out of stock
• I've tried manually entering an order to generate an invoice for them to pay the delivery fee but the email / invoice link goes to a page that says the product is out of stock

Any ideas on how to achieve creating an order and them paying the delivery fee whilst my products are out of stock? 

Any help appreciated. Aaron.