Looking for an additional ringer possibly with flashing light indicator for SWMBO's father who seems not to hear his regular phone (which already has its ringer set to its loudest setting). We don't want to swap the phone as it's a large-button one and he's got used to it. I daresay BT have something at mega-£££ but can anyone suggest anywhere with a good range of things at reasonable prices?
(FWIW we're in Reading, f-i-l in Henley, other relatives around Chinnor/Thame & West/High Wycombe.)