eCommerce Retail Invoice & Proforma Invoice from the same shopify Store

[WrightSport]

Hi, 

I am hoping someone can help/advise please.

I have 2 businesses that complement each other (currently with 2 Shopify stores)
1. re-seller/retailer of performance swimming products.

2. garment customiser for sports clubs/teams etc. (embroider/printing etc)

I am looking to put my customer orders through store 1. (and get rid of store 2.) and let them check their proforma invoice and pay via the Shop Pay that I already have set up, however my customers email or telephone in their orders (I don't want them to be able to order online). 

My question is, is there any way to create a second invoice template that I can choose to email manually to these customers, but still keep the standard automated one that the main eCommerce retail customers are currently getting?

I am pulling my hair out with this and really hope someone can advise, even if I need to look and an alternative set-up.

Thank you in advance!

Regards, Craig