I was trying to do something similar with LTC1799 precision oscillators and a bunch Korg DDD-1s.  The problem is that the LTC1799 can't handle too much load.   

I was thinking something like a breakout box featuring an LTC1799 into a high frequency distribution amplifier or splitter might be fun.

A good way to override the internal clock crystal is to hook it up to a 1/4inch jack that gets interrupted when a cable is attached.