wow pretty hardcore!
The iPad mini runs an app called MotionX-GPSHD. You can download terrain maps for any area that you want to explore (the iPad's 128GB memory limits how much data you can download but I haven't had an issue so far). Why pre-trip download? Where I travel cell site access is sketchy to none.
I have a terrain map with 472 tiles covering an area in the High Sierras of about 70 square miles that takes up 11.1MB. Think old logging roads at 9000'. ;-)
I have added the Baja/So Cal VHF channels to the iCOM radio but I have not been down to Baja yet. The channels that I programmed are in an Excel spreadsheet in four "banks":
A: So Cal #1
B: So Cal #2
C: GMRS/FRS
D: Local public safety
I uploaded the spreadsheet to http://www.azebra.com/Raptor/ICOM_Presets.xlsx.
How do you program an iCOM radio? There is a Windows app called IC-208 Programmer that is fairly easy to use.