Nodejs for real-time applications

Question

Recently, with the arrival of Angular2 beta, I have been looking for more information about real-time applications.

Currently I work with AngularJs (1.x) in the front-end with apache server in MySql & Php to the backend, what is not easy for this type of application.

I found some materials and have done some basic test designs using Angular2 and Firebase. However Firebase, despite being excellent and simplifying ENOUGH the work, does not supply the need when I need something better structured and elaborate, as an e-commerce, client portfolio, etc..

Reading more about this, or more specifically MEAN, I find it very interesting the proposal to use this set. But before I decide to switch to one or the other, I would like to understand more about this scenario.

Unlike the Firebase, which already has automated client-server communications functions, if you use a server on NodeJs would need to use some tool WebSocket, like the socketo., so with that I would like to ask some questions:

• When using my app with Angular2 in front-end and NodeJs backend, which would be a good database to use together? MySqlor MongoDb are the strongest options I have at the moment. The first for being what I currently work and the second for looking similar and already being in conjunction with the MEAN model. But if there is another better option, you will be welcome too. The only request is to have a good performance in real-time app.

• Should I choose to use NodeJs is it necessary to use some type of specific accommodation? Or these more common ones that exist in the market today already supply? Like Uol hosting, Weblink (currently used), Locaweb, etc..

If you have any further comments on the subject, please comment, as I am at a standstill in this backend language change and would like to know more before making the decision. Thank you.