I think you'll be happy, and you're welcome. I don't have a case for mine. I don't know of any but they are pretty durable. As long as you just leave them on a shelf or something when you're not using them and don't throw them around you should be fine.
As far as the amp, they technically shouldn't need one. But I have found they sound horrible with my iPhone but great with my Macbook. So your mileage may vary. If you feel you do then you shouldn't need an expensive one so the E11 should do. I'd wait to see how you like them first because it's probably not necessary.
The ONLY thing that I really hate about the COPs is that they don't have a 3 button remote. Since they are meant to be portable that really irks me. But since the cable is replaceable this will likely be remedied in the future.
And if you don't like them Amazon has an extremely liberal return policy.