Please note that you will have to install seperate transformers and use low voltage cable unless the fittings have a bulit in transformer (referred to as either Retro or integral electronic transformer).  Your electrician will be able to advise you with regards to what size transformer and how many you will need.

Where you are unable to install seperate transformers and low voltage cable (for example when replacing existing mains fed wall fittings) you will need to select the 'integral transformer' option (also known as retro)