I am facing exactly same issue

check out this app https://marketplace.jamf.com/details/exhibit

can provide more than just a single wallpaper

This looks like a good app Thanks, managed to download it, but looks confusing to configure, how do i upload photos? 

So you would need to deploy via MDM and deploy managed app config with it.

Here are all the various options - https://github.com/NU-ITS/Exhibit/blob/master/docs/app-config.md

As part of the process, you need to host a CSV file somewhere that the Apple TV can contact on a web server. In the past I have seen people just host it on a Windows Server and turn on IIS

In that CSV file, you can define where the images are stored. That way the device will pull the images directly rather than via MDM commands and configs. Also, you can have multiples and use it like a digital signage

Check out their demo content - https://github.com/NU-ITS/Exhibit/blob/master/docs/demo.md

Many thanks for your help, just got it working, only other question is there a way to remove the Airplay window that appears with the images, or this a way to change the text as it suggests I’ve called the Apple TV “Apple TV”  when it’s got a different name, which will confuse users when trying to connect

So all the configuration options are shown in the documentation. 
 

to change the device name you would add this key to you app config  and it will use the device name from jamf pro  

<key>edu.nebraska.ImageViewer.deviceName</key>
<string>$DEVICENAME</string>

if you want to remove the AirPlay window I believe it is this key

<key>edu.nebraska.ImageViewer.airplayViewHide</key>
<true/>

however it’s all documented on the app config docs link as above. 
 

once you are happy with your deployment and config.  Then you would push a config profile with single app mode to stay in that app

Cool, thank you very much for all your help, thats helped alot!