Personally I go the "other" way. Router + WiFi (I use an Airport, but pick your poison), and then the most basic modem possible for the location - this might be a provider-supplied DOCSIS Modem/Router in bridge mode, right now it's a provider-supplied "1 port" ADSL2+ modem/router in bridge mode. With an ADSL setup, you'll probably need to use PPPoE from the router, with a DOCSIS setup, the auth is usually on the MAC address so your router doesn't need to know anything, it just connects via IP to the bridged cable modem.
If the modem ever gives me issues, I'll just replace it with a plain-jane ADSL2+ modem. If the ISP's expand their docsis/fibre network past our new house, I'll just swap the ADSL modem for a DOCSIS modem/router in bridge mode.
This setup has given me the least headaches in every scenario across several houses in both Australia and Thailand. The only hard part really has been trying to express "I want a DOCSIS router that i can turn off the router" in a way that a Thai-speaking technician or my non-technical english&thai speaking wife can all understand.
As I said docsis is often MAC address controlled, so if you can't get the admin password to unlock the devices (http://portforward.com has lots of isp configs/auth details) you could buy your own docsis modem/router that supports configurable MAC address and simply spoof the isp provided device.
For fibre based devices usually you just have a ONT with an Ethernet port, so no modem required just plug in your router.
If you can give more info on the specific last-mile tech you're dealing with, we can probably make some suggestions.
