Sales/Onboarding

If I want to make this as a fully fleshed SaaS product, how would that work in practice? Will the client then need to add all their branding and specifications and knowledge base themselves?

Yes, the client would be responsible for adding everything themselves if you wanted to run it as SaaS.

If the solution is set up as a fully fledged SaaS solution, how does this work in practice after they choose to purchase the solution? If you could walk me through this that would be great.

Yes, the client would be responsible for adding everything themselves if you wanted to run it as SaaS.

Is there some «other way» / hybrid way to set it up where I market the solution, they choose which one they want, but I do the technical set up?

Yes, you can set up your payment options however you'd like. You can have a DIY model, you can have a Done For You model.