Hi there.
I see that you expect heavy data container on your server and that is the concern of the hosting provider that you will have to choose for your website. Most of them have a package that has "unlimited" storage but that comes with a price.
As far as unlimited pages go, that would be more plausible. After all, they are still considered as data, but not as bulky as pictures and videos.
Another thing you have to consider is the physical hosting provider that you will choose. If your targeting audience is mostly from the US, then you should choose the service that is located there.
Now, for the website part. I would go with a Material design (provided by Google) that will at the same time be clean and responsive as well. Most of my recent designs are done with that library.
You can see some of my work on my profile page, so feel free to check it out.
Anyways, feel free to hit me up so we can talk more about this. I am very responsive. All the best