I have no idea why this kind of thing is so hard to find. does anybody use a dedicated bluetooth number pad with their surface?? I do a fair amount of numeric entry and this would make the surface hugely more functional to me. I'm just looking for something simple, I don't need a whole lot of bells & whistles. a lot I see on amazon are getting mediocre reviews at best. some have a built-in calculator which is clever, I can do with or without. I want one that just works, is compact, and hopefully black to match the surface. the Microsoft Bluetooth Number Pad looks ideal but for whatever reason seems to be out of stock just about everywhere. anybody got any recommendations??