I found a very inexpensive way to use a tablet to navigate GAIA GPS or Google Maps. Tablet, BT GPS, Tablet mount and necessary apps for about $150! I paid $148.26 +tax.
*Disclaimer - There is a short, simple process to make it work. You have to go into the settings, get into Developer mode to be able to enable Mock Location. Very simple to do. Then it works like a charm.
Tablet is a Dragon Touch M7 on Amazon for $69.99.
GlobalSat BT-821 Bluetooth GPS on Amazon for $48.34
Mount is iBOLT TabDock Bizmount AMP's on Amazon for $29.95
*Prices were at the time I ordered the items.
Google Play, the apps were free downloads: