Hello, I have seen the general requirements you have on the widgets, and I am the right person to create them.
Since I am new to the site, I propose a first milestone where I will deliver the WIDGET 1, so that you can trust my work to complete the project.
I have an estimated 10 days since I still have some questions regarding the project, but I think that everything can be done in a shorter period of time.
I have some questions concerning the framework (or CMS) that manages the site, as well as some related to the level of interoperability that widgets must have with the site (for example, tables in the database that must be modified, if this is the case).
I can use both a free or a paid API, once I know the complete requirements, we can talk more about it.
I can make the project on PHP, and javascript since I see a level of dynamism the widgets require, of course I will also use CSS to make the widget very visually similar to the examples presented.
Have a nice day.