Your Ecuador's carriers, Movistar, Claro and CNT, use LTE bands 2, 4 which are in the ipad as well. I don't see a problem.
Get the iPad mini 4 WIFI plus Cellular
Make sure you backup to itunes and do an encrypted backup so you can restore all your passwords to the new ipad
You could even get the iPad Pro 9.7, it has 2 more channels then the iPad mini 4, but you won't need channels 12 and 27 in Ecuador
Ipad use the same cellular chips as iPhones. If the iPhone works with the SIM card, then the ipad should as well
However. Some phone companies don't like you putting a SIM card from an iPhone into an ipad, because you might end up using even more data.
The apple sim or the apple's cellular setting mights not allow you to activate the SIM card inside the ipad. So you should still be able to pick up a SIM card thats already activated.
The final word is apple itself. Apple's LTE page says Movistar is supported. So go ahead and don't worry about it
http://www.apple.com/ipad/LTE/
[doublepost=1467313902][/doublepost]You do not have to get the carrier it comes with it!! The iPad mini 4 is universal. It will work with anything
You don't need to buy an " AT&T " version, you do not have to buy a " Verizon " version.
That just tells you whose SIM card is in the box
Back in the day you had to buy eiher the AT&T or the Verizon ipad. That was 6 years ago
That stopped entirely when the iPad Air came out. Its these android and amazon knock offs that continue to make you decide whose carriers model to buy
With the current ipad. All you have to remember is , if your in America, and you want it on Verizon your going to need a Verizon sim. Thats all