The final traces of the four layer board are completed and the stepper motor drivers are hardwired into 1/32nd microstepping mode.  I will be ordering it from OSHPark this weekend and the components from Mouser, as that is the only place where the STSPIN220 is available at the moment.  

Next is to consider the thermal properties of the board and design the 3D printed mounting case with integrated cooling fan and vents.