We had a old BT 4 handset Dect phone system at home, sound from the handsets wasn't great and when somebody called the landline they all rang and often woke our son up.
So I bought one of these
http://www.johnlewis.com/panasonic-kx-p ... =232330904Its a single handset and base station with answering machine. Difference over the old one is that you join it to your wireless and then via an IOS or Android app you can add your smartphones as handset extensions.
Once done you can send mobile contacts to the handset and also make calls using your landline from the smartphone. There is also an intercom function from the handset to any smartphone you register as a handset.
Works really well as I always have my mobile on me and have set the alert to vibrate as well, got rid of 3 handsets plugged in around the house.
There is no internet pass through with this, so once you are out of reach of your home network you can't make calls. Also found that all devices have to be on the same SSID. I have a 5GHZ SSID at home for IOS devices and found that the phone joined the 2.4GHZ network, so I had issues joining mobiles if they weren't on the 2.4GHZ SSID.
Best price I have found for this is John Lewis, Amazon want £160 for it.