Business Multiste set up

Hi there, I’m planning to set up a multisite blogging network and need some help.

I want to be able have pre-made themes configured so I can sell to my team.

I know how to create and configure the themes, but don’t really know what plugings I should use to sell the themes or how I should do to showcase the themes.

For example, I want that they can choose the pre-made theme or later on any of the pre-made themes and then pay for them and the site will be live right after the pay. I want that they can also use one of the sub-domains offer by me, transfer their own domain or buy one from the site before paying.

The other thing Im not so sure is if I will need to install whmcs platform on a domain on itself and the multisite on another domain or the whmcs platform on a subdomain on the same domain of the multisite installation.

Another thing is I’m not sure how I should calculate the amount of data (bandwidth), storage GB etc… for every site. Right now I’m on a shared hosting optimize for multisites until I grow enough and see the need to pay for a VPS or Dedicate Server.

I looked at the pro-site pluging and couple other pluging but not sure if just the plugings will do it or I will need the whmcs platform and the some plugins to accomplish this project.

By the way this site is something similar of what I want to do. I really want to have the process as much on autopilot as I can. I hope this make sense

This is the similar site I was talking about:

Thanks for your help