Benchmarks and Ideas for a Client Portal (Service/ Consulting Business)

Hi, Guys! This is my first post here, so bare with me

I've just recently started working with CS, and the company I work with is a cybersecurity reseller/ consultancy firm. So, we partner up with companies like IBM, Forcepoint, OneTrust etc, and intermediate the sales process between both. We're also responsible for implementing and giving support once the product is installed. So, I believe CS works a little bit different from Sass companies.

So, anyways, the company wants to build a client portal, where technical clients can see the status of their cases, and executives can also see the cases, but mostly contact information, contracts information and so on.

I'm clueless about industry benchmarks and searching for ideas on:

1. What information should be available in a client portal
2. Should it be free? And should it be available for all clients or only "top tier"?

Any information/ help will be highly appreciated. 
Thanks,
Larissa.