New router or all in one?

I am getting ready to cut cable and go all online. To do that, I need to get faster Internet and a new modem or router to provide that speed. What would be better, getting a router and bridging it with my Motorola 3347 for a 20mbps connection or getting a new combo like the Zyxel C1000Z? My house is capable of 40mbps, and I want enough bandwidth to have multiple devices connected while streaming 1080p movies to my TV. All of our connections are wireless unfortunately.