I use the same RAM Double suction cup mount as we use at the Airline (see TXCUB in this thread-same mount) . Works ok-Sometimes pops off of its been awhile since I re-sucked it. its sucked on to the wind screen. I have a Lynx NG9000 ADS-B, and it now shows traffic via WiFi on ForeFlight or WingX Pro on the iPad .
The smaller iPad would be better, but I'm too tight to buy one just for the Cub plus data and subscription to ForeFlight again.
With one ForeFlight subscription you can run two iPads and one iPhone.