PPT template build based on designed pdf version

We are a design agency and design ppt templates for our clients but need help when it comes to the build. Turning our designs into a ppt template version for clients to roll out internally (setting fonts, headers, backgrounds, colours, themes etc) - based on our designs - to make it as easy as possible for clients to work within the examples we design.

We want them to be able to change imagery, text, add slides and new content and help them keep within the templates designed.

Attached is a current project we need built in ppt