Advice RE Trapeze Lighting Systems

Hi I was wondering if anyone could reccommend a lighting supplier in melbourne metro for a complete trapeze system, the area for use has an exposed truss, pitched roof and I require it for the kitchen area, I also have concerns about the life and quality of the transformer as I wish to have it located in the wall cavity and switched on off typically ( perhaps this is not such a good idea and it is better located with better access maybe boxed as I believe they have limited life) The system will be fitted by the electrician I would appreciate if anyone could share any information with me.
Regards Simone