Integrate a Saas boilerplate with new apps and deploy to Linode

I am looking to start asap a project to build a simple Saas platform.
To summarise, the project would look like this:
-I will buy a Saas boilerplate so you only need to install it, customize the main page and integrate with the supplied tools(scripts).

Client subscribe to the service via the main website name (example.com).
-After the client successfully signup and login to the site, they can access the apps (I will provide the open source apps available on GitHub).
-All the scrips need to be hosted in a version control system as Gitlab/Github and deployed to production.
-Project will include stage and prod environments
-All the apps need to be proper documented and deployed to production on Linode (I will supply the server)

Similar example app can be found here https://www.upguard.com/blog#compliance-regulation

I have some Saas boilerplate in mind (laravel, javascrip, django) but I am looking for your advises to see which one to use.

Let me know if you are interested in this job.

Thanks again for your time.