Probably the most common arrangement is an "L" bracket with a Vivitar 283 and cord to fire it from the lenses PC socket. Some of the Mamiya's were early enough that you had a slider to choose between electronic flash (modern strobe) or flash bulbs. Leaf shutters can "sync" at any speed. Usually the flash itself is the determinate factor and shutter speed doesn't matter. I'm sure there are more sophisticated flashes, but I gravitate towards the old 283. Simple, direct, effective, and tough, just like the Mamiya.