I am looking to buy this model of phone. Can anyone tell me how many handsets it will support? My current system of BT phones is base station plus 5 additional phones (1 in office remote from house) with a BT repeater. I would like to replicate this system with the call barring facility. I am not sure if I can buy 2 base stations, 1 for office, 1 for house, then make up the required number of phones? This might make the calls clearer in the office.