I'm only new to this, but am thinking about wireless flash capability. I have a canon eos 350d and am looking at the yongnuo flash units. I understand that I will also need transmitter/ receiver (yongnuo rf603). which flash would be best? 565, 560 mk 3, 568 or none of the above? getting confused with the master / slave terminology. do I need wireless transmitter/receiver and a master capable flash or will I get away with slave flash?