I always use the landing light in the circuit and when I hear that there is possibly conflicting traffic ahead of me. I was encouraged to do so when, after being given a long straight in approach to Yeovil, their ATC told me that they could see the light long before they saw the aircraft.
It is so long since we changed a bulb I cannot remember the type and I am not trawling back through years of records to find out. All I can remember is that we bought replacement bulbs from B&Q for a fraction of the price quoted by Airworld at the time. (PtF aircraft)