Best file upload approach

Question

So, what do you guys recommend to start off from in order to achieve the functions below?

1. Multiple image file upload
2. Resize(compression) images
3. Upload them via ajax (automatically) even before the form is submitted.
4. First image is the "main" featured image, and others are given custom post meta
5. For multiple images, there are radio buttons which users can choose which one becomes the main image.
6. Once form is submitted, any changes (if user changes the main image) will be updated.

I tried to build something from scratch but it is taking too much time.

Any suggestions will be much appreciated.

Answer 1

1. My way:
   • 1.Use plugin for multiple ajax upload
   • 2.Plugin for resizing images
   • 3.Change main image trough ajax