Drop servicing design products

[JohnSmith420]

Hello guys, I need help to complete my store. I'm building a design agency and I need an app for customer checkout and order processing. I need to collect some customer information, regarding the order, before checkout and save it for later use. After that the designers in the website need to complete the order and upload it through some sort of panel to the customer profile.  The system could work through chat like the one in fiverr too I think. I'm trying to implement this, or find an app that does that, but unsuccessfully for now. I'm not sure which of the options is more appropriate for the store. I could try to implement this if I can't find an app that works. Thank you in advance for your help. My website is https://design-mastery.com/