You want the shortest bulb life, that way you get the most lumens per watt. If you want less light and the same colour temp, Get an ELB, it is 80 watt 30 volt. It has approx the same light output as the long life ELCs with way less heat. have what you need, as long as your London is a north American one and not the more well known one in the UK. An ex SW2 resident.