Configuring wall mounted monitors to show a looped slideshow

A new client has 7 new large screen monitors attached to the walls of their training rooms, break rooms, conference rooms and as you enter the lobby.
In their old building, they had one monitor that ran a looped slideshow of the company had created showing the different products that the company manufactured.
When they moved, they did not bring over the old equipment that was attached to the monitor and no one knows who configured it.

They have asked me to come up with some options on how to display the looped slideshow on these monitors.
They have also requested that they have the ability to run different slideshows on different monitors, ie:
The one in the lobby is for welcoming new visitors
The ones in the shop would display company news
The ones in the break rooms would display company news
The conference rooms would be similar to the one running in the lobby.

I need to know what kind of hardware and software I would need to purchase for this to work.
Thanks in advance.