DanielWLand

You've gone for a minimalist theme and done it very well in my opinion, but spoiled it by having a landing page. It doesn't add anything,and just adds an extra click to get to the information the user wants. In that respect it's inconsistent with layout of the rest of the site that says that it's all about getting the information to the visitor in a responsive format.

The content isn't so much of a problem, if the old site dissapears google won't penalise you for plagiarism. If the site is decently engineered there's no real issue getting your content indexed anyway, that's the easy bit. A brand new site submited to google with no incoming links can generally expect to be indexed within a few days.
 
The only way to hold onto that page rank is to use a 301 permanent redirect. However, if the customers don't want any link with the old company name, they're going to have to say goodbye to that and start again from scratch.