I'm very new to this since at the office where I work my boss requested to show some world digital clocks since we work with customers from several countries.
After investigating we spent some money in 8 LED Matrix + XU2 controllers, they were cheap and easy to program, since everything goes through a WYSIWYG software. This was about 2 months ago, and we were very happy with them

The problem is that they desync about 1 minute every 2 weeks, and that's very inconvenient, because we need to sync them one by one through a static configuration file generated by the software through the USB.
The controller is this one:

I'm planning to buy new controllers for the clocks, but I need something that can sync through NTP with WiFi. I don't mind learning some programing, it's a lot of fun

I would be so happy if somebody could help me with a nice device, we don't want to spend a lot but I'm sure there are some nice devices not too expensive.
Thank you guys!

P.S: Sorry, I forgot to tell that the LED Matrix we bought are 64x16 dots.