Nic,

We have a saying here, "There's many ways to skin a cat", which isn't the most politically correct thing to say.

I don't know that your needs really do demand an external midi sound module. You could do this with soft synthesis, but I'm not well-versed in BIAB and how it commands a synth. There are plenty of multi-midi-channel soft synths that could do the work, then you would use the Saffire for all connections to you PA.