David Partridge used an interesting and effective scheme to synchronize outputs on his divider board (no longer available) that could output several different frequencies that would all start at the same time. I have one of the boards he produced and it works great. Here is the description of the circuit that might be of help.
http://www.perdrix.co.uk/FrequencyDivider/
I have done the same thing but to minimize phase noise and not to align the outputs. Variations and noise in the supply voltage to the divider chain introduces jitter and it is easier to reclock the outputs than to produce a low jitter divider chain. Even a 500 MHz oscilloscope would not show it but a sampling scope sure will.