Mike D. wrote:
I already have the Stratux with the dual frequencies.  That means I have two open USB slots (I suppose I could add a multiple USB adapter).  Will the AHRS, and other modules be available at OSH?
 
The AHRS, pressure sensor, fan controller, and G-sensor are all on a thumbnail-sized board that attaches on the double row of pins on the Pi board, so no USB slot is needed to add that functionality.