Zyxel C1100Z Failover - 4G/5G LTE Modem

Damien7592
Damien7592 Posts: 1
edited August 26 in WirelessLAN
Good morning, 
We are a small business in Denver, CO, that relies heavily on the internet. Century Link is our provider, and our router/modem is a Zyxel C1100Z. We have an ethernet switch for our network. We want to install a failover router to our Zyxel C1100Z in case CenturyLink is down.
I'm not an expert but after doing some research, it seems that I could set up a failover modem and a double wan router (Zyxel USG Flex 100) while keeping our Zyxel C1100Z in a transparent bridge without a load balancing mode.
Could you advise which double wan router and failover router I should get for what I'm trying to accomplish?
Thank you for your help.