Planning development of an application, looking for advice.

Lets take a moment to dicuss Front end frameworks, in a nutshell ofc.

AngularJS uses 2 way data binding to store user input. Besides that it uses a rendering technique that renders the entire html. It's also written inside the HTML (some of it). You can see it as "javascript inside html". Angular2 uses a similar method, only this time it's built with compenents which are injected to one another.

React takes a different approach. It has a virtual dom, the HTML written inside the Javascript, and it uses components and render only what needs to be rendered at the same time, by comparing its virtual DOM, to the DOM you see on the screen. And then ofc, there's the "Icing on the cake". ReactJS unlike many other frontend frameworks, uses uni-directional data binding. Meaning the data in your application flows only in one direction. There's no button that by clicking on it you send a request to an API, for example. In my opinion it makes an application easier to reason about, where you know exactly where this piece of data came from, and how to trace back to the source of data flowing into your application.

Pointing out a personal opinion: I prefer working with components. I prefer bit size chunks of HTML that are injected when they are required. I also like when my HTML is not loaded with directives and so on, so I mainly like to work with Angular2 and React

It's like asking if you should buy an iphone or android. If you're building a full javascript-based site then the tools are simply a matter of what your team is most comfortable with. Node and express will most likely be your back-end language, if you don't need a schema then plain mongoDB works, otherwise, mongoose adds structure with a schema-like design while keeping everything stored in JSON (BSON). As for Angular 2 or React, that just comes down to preference. Both are capable. Going back to your database question, that also depends on how you're going to host your data (firebase, AWS, Heroku, company server/db).

In short, your question is opinionated. You've defined the language, You've defined the format, now it's simply a matter of preference.

NodeJS is asynchonous, meaning you will be able to get data from several API in an unordered manner. If you wish to be a main-data-source getting its data from many other sources. This can come in handy. MongoDB can be good if your deta veries from one source to another. Lets say, if one of your costumers have 3-4 fields of info, but another has 6, because your data sources could tell more about your second costumer, than they could about your first.

AngularJS/React/Angular2 are front end frameworks, which means the decisions regarding these, requires further thinking. which is about how to display the data and selecting the right approach. I'll expand on these in a few hours (I got to go now)