Not exactly familiar but I have worked with smpte syncing a bunch of blackface adats to a ProTools rig using an Alesis BRC as synchronizer. Motu works on similar principle and I know it prefers to be the master clock of the system. But to be honest, man... that was several years ago, although the principles haven't changed since then and I've been keeping up to date with new technology. Been too busy with my small project studio, so there! :D
No handle on DUC, man; I lurk there every so often. I'm mostly a mainstay at the Sonar and Emu boards. Anyway, as to your dilemma, Motu is pretty much the way to go but if you got more budget, the Apogee Big Ben
has the most stable clocks of all- big bucks though (shudder). I once evaluated the Motu, the Timepiece A/V would be perfect if you're going into video too. Did you check out the Otari link for their synchronizer?