Interfacing APM with Arbotix

Hey

Two amazing products of arduino community are "APM" and "Arbotix (the electronics of Phantom A hexapod kit)". i want to customize my hexapod kit and thus need to interface APM with Arbotix such that the sensor data could be received (in the form of position) to the controller of Arbotix card for autonomous navigation.
cAn anyone plz suggest means of doing that? i have software serial available on arbotix card where the sensor data could be interfaced.
i want to ask whether inerfacing two embedded systems is okay? i have experienced that importing libraries does not enable one to understand the other!!