I decided to go with an iPad Mini 4 and the P4P! Decided I want a bigger screen and have heard nothing but good things about the iOS version of the app. I was able to get one Wifi+Cellular refurbed from Apple for the same price as a new mini 2, and ultimately with the drone will cost the same as the P4P+.
Congrats on the decision --- I don't think you will be disappointed at all.
And what sort of sun hood to get for it...
I recommend the Hoodman. Amazon.com : Hoodman Drone Aviator Hood Kit (Includes HAV1 & HAV1E) : Camera & Photo
I originally purchased the DJI RC monitor hood which is ok, but the Hoodman really helps to make the iPad mini display much brighter because it completely surrounds the iPad mini. I also like that it has an removable extension that allows for use with glasses.