Hey. Hey...
If that is pretty much all he wants to do then the "pro" versions would be overkill. Any of the others would be fine. And the wifi only would be just fine. However; if the 12.9" screen is your liking, then this pro version is your only choice. Wifi and minimal storage should be fine
Now that being said...if you use apple iphones any of the ipads would be a perfect fit since apps and usage would pretty much be identical. Even if you don't use iphones would still be fine but tablet would be more user friendly with the android operating system
I've been in both camps. A big apple (ipad) user. Now is my "go to" device.