The conversion of Watts to Amps is governed by the equation Amps = Watts/Volts so if you check how many Watts your bulb(s) will be, you can work out what amperage flex or switch you will need. For example 4 watts/240 volts = .016 Amps for 1 x 4 Watt bulb.
Our Bayonet Cap Lamp holders are generally 2 AMP rated and our ES lamp holders 4 AMPS. Our Flex specifications can be found here.
We are not qualified electricians and only offer guidance, which can change. If you are not a qualified electrician you should always get any electrical work you do properly checked & certified.