Simple software to run church sign

[algerdes]

I am at a loss today as to what to use for our new project.
We are purchasing enough P5 panels to make a double sided marquee at our church.
The purchases include two ColorLight cards.

If this was being purchased for any of our animated Christmas displays, the choice would be simple. FPP on a RPI feeding the ColorLight cards.
This requires the use of a sequencer (such as xlights) to provide the images.

The hesitation here is that this will NOT be part of any Christmas show, but will be used year round, and on 24 hours a day, to announce events/happenings/get-togethers at the church. Yes-graphics will be involved. The kicker here is the church Secretary will most likely be the one to change the display whenever needed. (Weekly at the least.) I need to keep it simple to use and maintain.

What would you use to create and then send imagery to a setup like this?
What additional hardware would be necessary or prudent?

Thanks in advance
Al