I think the problem with your spec is the dual-band WiFi. Without that I would suggest the Zyxel VMG1312-B10A or VMG1312-B10D, which get favourable reports from several members here.
That would be my recommendadtion for a smaller budget. If dual band wifi is a must then you can pick up a Zyxel VMG8324/8924 for a bit more.
Thats if you go down the single unit approach.
I always have a seperate modem and seperate router. I can reboot the router and tweak settings, drop the PPP session etc, without disconnecting the xDSL connection which is maintained by the modem.
This setup also allows the modem to be placed at the master socket, and an ethernet cable to be run to the routers preferred location, while maintaining the maximum possible sync.
I'd again recommend the Zyxel VMG1312-B10A run in bridge mode as a modem only for this setup. That leaves you with a huge selection of routers to choose from without needing an xDSL chipset inside.