I'll chime in on my iPad install. This writeup was done last year...
I opted for a iPad 2 64GB 3G (Verizon) to save on the initial investment. I only use the iPad for couch surfing and in car navigation. 3G allows for GPS without WIFI.
Install in a 2008 FJ Cruiser:
Ram mount mounted to 1 1/4" x 1 1/4" square tubing (Lowe's) The holes allowed me to 'assemble' without the need to weld.
Square tubing doubled up to allow the arm more articulation.
I chose the generic Ram mount for the iPad as I utilize a Otterbox Commuter series case.
Setup is solid, very little movement offroad, easy to adjust and allows multiple viewing angles for driver or passenger alike.
Mount also folds flush if iPad is not in use.
Apps installed are MotionX, Gaia GPS, CoPilot Live, MyTopo Pro.
MotionX is a fantastic app (recent IOS changes make this less stellar.) The only issue is downloading maps via WIFI. I've had downloads take 5-6 days for bigger files 1.5GB. I wish you could download to your computer and then upload to the iPad. Gaia GPS has become my default navigation app.
I use my iPhone as a hot spot when I have cell coverage to cache maps, but I still have downloaded about 20gb worth of hybrid and TOPO maps on to the device. The zoom settings I use are 10-16.
Charging is done by a 2.1amp USB charger added into a (always hot) 12v source next to the glove box.
(1x) 1 1/4" x 1 1/4" x 36" square tubing (Lowe's)
(2x) 1 1/4 square furniture caps (Lowe's)
Black spray paint.
Let me know if you have any questions.