mobile

Not sure if this is the best section to ask this in...

I need suggestions/advice picking out Hardware(tablet+accessories) and Software/Firmware.
I need a tablet or large screen phone to act as my Motorcycle's Navigation and MP3 player.

I don't know if there is a product already out there that can do all I want reliable, or if something could be made to work with custom firmware?

Past experiences:
I have an original Nvidia Shield and a Lenovo mixx 2 8 (windows pro tablet). Both with on board GPS, but the mixx is very buggy for gps, and I can't find very good gps software ether. The shield is not bad for GPS, but clearly not meant for my application.

Basic Features:
-6-8" screen (not including chassis)
-stereo out (headphone jack or rca or something)
-Can be configured to Navigate and play MP3s easily at the same time.
-Fast turn off/sleep/etc
-Unassisted GPS, built in or usb /etc
-Can charge while in use.
-Easy to use, reliable, smooth to operate.
-Memory card slot or 16gb+ storage for music.
-I'm in Canada, and sometimes ride to the USA, so if that's a factor I'm making note of it.

Looking for suggestions for what tablet/device options I might want to get, and also what apps or firmware would complement it for my purposes.

Thank you very much for your help and time.