Can I use a keyboard for Apple? I want to buy a mobile Bluetooth keyboard.  It seems Apple ones are easier to find.
Does it make much difference?

(I assume the connection is the same for similar models, and the issue is layout)
I have used a couple of different BlueTooth keyboards and they all work pretty well on Android. I would assume the Apple keyboards would work just as well. I am a fan of Logitech keyboards just because I've always used them and they have always worked. You can always just buy an Apple keyboard and if it doesn't work you can just return it.