I'd make it dependent on the form factor. Wait for the Pro, see if the size works for you. I had tried some 13" tablets in the past, and they all struck me as impractically large, even though I thought they'd work for me. But this is very subjective, really.
For the Air 2, you'd want a Logitech Ultrathin keyboard, which is around a hundred bucks, but far superior to anything else I tried.
I feel it is also worth considering that the Pro will be a first gen device.