Home setup question with Zyxcel Centurylink router & 100mbs service

After not having success connecting my Sophos Firewall to the Centurylink ONT directly, I'm trying a new approach.

Has any one set up Sophos Firewall with this configuration for Sophos Firewall running on your own hardware (Home Edition)?

• Centurylink 100mbs fiber terminates at ONT
• Connect Zyxel router to the ONT.
• Connect the Sophos firewall to the Zyxel router.

I would still like my Sophos Firewall to get all the edge traffic so that I can do VPN, etc.

How should I set up the Zyxel router?

1. Bridge mode (if possible)
2. Some sort of DMZ configuration
3. PPPoE Passthrough if allowed?

I'm thinking Bridge mode is the best way to go.