>The problem with the OO gear is that there is no bridge mode …

  You don’t say what type of router/residential gateway your ISP gave you, but most of them have an “IP Passthru” function that allows you to delegate the gateway’s Internet IP to another Ethernet device of your choice.  If you enable that and turn off all the firewall rules, then it’s pretty close to a bridge mode.

  For example the BGW210 and BGW320 used by AT&T out here both do that, as do their older VDSL modem/gateways (e.g. the NVG589).

  I suggest Googling whatever your gateway mode is and “passthru” and see what you come up with.

Bob