Developer needed to create customizable functionality on Shopify store

I have a Shopify store that sells greeting cards, but I would like users to be able to customize the inside of the cards and add their own message. Here's some more detail: 1. The outside of the greeting card won't change, just the inside. 2. Users should be able to add whatever text they link inside once they have chosen the greeting card design. 3. I know there are customizer/personalizer Shopify apps that allow this functionality, so I am happy to use one of these if someone can help with integration and customization. 4. Once a user has checked out and paid for the card, we'll also need to be able to download their artwork as a PDF so that we can share it with the printing company. 5. There are some greeting card companies out there that already have this functionality: [login to view URL] and [login to view URL] are just two of them. 6. I have attached screenshots from Scribbler's user journey, which is exactly what I'd like to be able to offer my customers. If the above is something you are able to help with, it'd be great to have a chat and discuss your solution, costs and timings. Let me know if you have any questions. Thanks,