Need for a single phone device

I still need the following phones at my home: a fixed internet phone from zingotel, a usb-drive based internet phone from magicjack which I carry with me when I travel, my cellular phone and an intercom phone for the building security and other residents to contact us.

I have not mentioned our landline and my family’s other cellular phones here.

Altogether, these are a lot of phones and sometimes we have to run around between the different rooms to reach these as we hear a ring.

A cordless / blue-tooth protocol and equipment to receive calls from all these to one phone device would probably be helpful.