witch is the best apple tablet on a budget to use all feutures of the phantom 4 pro?

ipad mini 2, ipad mini 3 or a ipad mini 4 ?

iPad mini 4, if you can stretch to that

The Ipad mini 4 is the only one who inherited the anti glare coating of the Ipad Air 2. Therefor it is the best choice.

I'm going after the mini 4, then my wife can have her air2 back. The air2 is nice but I think even though screen is big it's really almost cumbersome to have it on controller.
But i want the processing power of the mini 4 and smaller screen size.

I use a mini 2 and love it.

But since you said on a budget, I'd go with the iPad mini 2. $199 at Wal-Mart I have two 1 for Phantom and 1 for Mavic.

I have been using the Mini 4 since its release and it is absolutely perfect. Has the speed and the size is just right.