Multisite network with limited themes

Hi,
We need to setup PlanetWellness.com so that visitors can select a sub-domain, select a website design based upon a limited number of theme options and pay via stripe. We'll then collect information from the client and configure the website for them. We'll then set their user privileges for the client to create blog posts, etc. I need to accomplish this fairly quickly. Do you have a tutorial on configuring using your plugins/themes?

Thanks,
Erik