Custom website or LMS?

Hello all, was hoping to get your thoughts.

What I'm trying to do is complicated (at least to me it is ) but this is the best of analogy.

Goal: Imagine trying to take an entire encyclopedia and turning it into a Articulate Storyline (AS) presentation and then sell subscription access to the information. The intent is not to ever sit through the entire thing, but to reference it every once in a while for necessary information.

So......

I've checked out many of the LMS options out there and they look great, low-cost and fairly easy to use, but their designs are a bit rigid. There are no course "sub-categories." You can only offer an entire "course" and then have subcategories in the actual coarse itself and each course usually has file size limitations. For a user, this design would not be easy to sort through an encyclopedia.

I'm thinking this: Organization website -> Shopping cart -> Paypal -> Provision of log-in and password -> Access to copyrighted material -> now I can create the webpage with many buttons that bring up AS presentations and presented in anyway I want with subcategories.

Thoughts? I'm very open minded. Just struggling to find the best answer.

Thanks!