Right now, my x0xb0x emits MIDI clock sent to a DR202
drum machine.
I may be missing something, but can't you just run the midi clock
into
jack, and then split it to two independent midi outputs, and then to
your synths?
If one of your synths has "MIDI Thru" you don't even need your
computer, just get the clock to both of them over one midi chain.