Panasonic indeed makes good phone. I would suggest have a discussion with Airtel call centre and ask them to change the current phone to cordless (assuming current one is with cord). I am sure they will be able to replace it and might charge very less. Else Panasonic, cordless phones are good and they are reasonable priced.
There are several brands and different types of phones available so what do you really are looking for.
I am using panasonic handset with a base handset attatched with bsnl line and handset being a cordless along with other two handsets so a set of three cordless.Another two only needs power outlet to charge with battery drains no wiring or anything.
It has an answering machine with messages storage upto 20 msgs.
Panasonic, Beetel,GE are the most selling brands.