Rebuild an existing Ionic 1 app to Ionic 4 (or Ionic 3)

I am looking for a long term relationship as I will need a lot of changes to the app in the future. I have a simple app build in ionic 1. I want it to be rebuild it from scratch to the latest ionic version. Preferably Ionic 4, but also Ionic 3. You could suggest the best alternative. The app is used by a technican for logging data/observations in the field. The data is beeing sent to an API and when the report is complete, a pdf report will be created and sent to the customer per. mail. (All this is handled backend and is not part of the project) This app is communicating with a postgresql database through a REST API build in node.js The project is about building a new frontend with a modern and simple look. Backend is running and we may reuse the same routes, used by the Ionic1 app. Todays app have about 30 html pages including: *Login-screen *Main-Menu *A couple of list view reports (Simple get requests) *My Profile page (Simple get requests) *Customer search *Create a report About 15 of the pages is about creating the report. The most "complex" functionality is: 1. Signature-Pad. The report should be digitally signed and signature should be uploaded to the database 2. Photo-function. The user should be able to take photos with the tablet and send them to the API. The picture should be uploaded with the same size independent of the input size (might need to be resized to a smaller format before uploading) The rest of the pages is just about taking written input or select values from combo-list. Further details will be shared when I have chosen a freelancer