Need help with picking a keyboard for my iPad

So I'm thinking about getting a keyboard for my iPad and I hope to get some recommendations/tips from you guys.

I own a 3rd gen black iPad (aka The New iPad) and I need a keyboard with an adjustable hinge. I currently found three options:

1. The Brydge keyboard

2. Clamcase keyboard

3. Sharksucker keyboard

Which would you suggest? Maybe there are more like these that I am not aware of?