Hi there and welcome
The iPad has the sensors but it only has Assisted GPS, not an actual GPS receiver so you need to ensure you get an iPad with the 3G/LTE option. Even without a Sim card in it it will still get the GPS from the cell towers, and provides good GPS while flying.
The iPhone is the same, but as it always has a Cell tower connection it has no issue with GPS.
So to summarize both devices will work, just make sure you have the mini-ipad2 with 3G/LTE.