GPS, BLE, 9 axis IMU part suggestions

[GeorgeJr]

Looking for some suggestions for parts.

Main custom PCB Board has a STM32F401 MCU with connectors to add a Hat.
3.3v with I2C and UART and likely will have SPI available for the hat off the main board.

What am I doing with this hat:  Hat is for 3mph or less rocking vehicle to provide heading and speed adjustments.  Looking to average 10-15-30 sec of data and make correction if outside acceptable speed or heading tolerance.  Clear visibility for GPS.  Sensors are for heading and help with low speed where GPS isn't as accurate.  1/10 mph speed tolerance for speed adjustment or so is desired and heading 5 degrees or so either direction (adjustable if more deadband is needed for both). 

GPS was looking at SAM-M10Q  also Quectel L89 (Dual band L1&L5) or ?   Wondering what others like/dislike from hardware to using data in code.

IMU:  Was looking at 9 axis but seems many are 6 axis.  Any suggestions on parts?  Starting looking at ICM-20948 but would need to shift the output.  BNO085 was another one I was looking at but looking for suggestions here on what works well.  Minimal calibration would be a plus as controller might not be easy to access.  Also any issue mounting vertical vs horizontal?

Bluetooth:  App for iOS and Android future state and would like to have enough flash to update the firmware in the future.  MGM240PB32VNA3 from Silicon Labs or a Nordic chip or ? 

Thanks for any suggestions.  Will build and test first but long term would be larger run say 500 boards so some cost will come down with larger order.