What you’re wanting essentially is to not have to intervene, to let the customer do it all without needing human intervention by the company other than when things go wrong, am I correct?
Of note, WordPress.com already operates in an environment where the end user can do it all themselves.
I estimate the time needed to build this as 2-3 days. I’m afraid there isn’t anything that will do it all for you straight out of the box. The others have very nice solutions that let you modify an existing wordpress sites design extensively without needing to do any code or stylesheet work, but as you’ve mentioned that’s not what you want.
So you need:
- A multisite, or a root install, that sets up a new WordPress site/install from your own custom distribution ( rather than the vanilla wordpress install ).
- A plugin in the wp-content/mu-plugins folder, that launches your wizard by redirecting on login the first time a user logs in, and then never showing once the wizard is completed
- Alternatively instead of the above you could use a customised installer, see http://www.kurtpolinar.com/wordpress/create-a-custom-wordpress-installer/ and http://wpbits.wordpress.com/2007/08/10/automating-wordpress-customizations-the-installphp-way/
- A page showing themes and a next button here is how to change the theme in code
- A second page listing the plugins you wish to offer, here is how to activate and deactivate plugins in code
- A final page leading to the add/edit pages menu item so that they can add them. Alternatively it can redirect to the admin page of a bulk page creator plugin instead
All the themes and plugins would come preinstalled with your multisite network/wordpress install package, all you need to do is that last step of building the Wizard GUI
I would advise that you’re problem of clients not being ready for custom design is not a technical problem, nor is it a problem with their knowledge, but a marketing/sales problem, and one that could be very profitable if it’s solved.