I have the Stoway BT Keyboard, and it works great. I know another user on this board who has the Freedom Input BT keyboard, and I have seen him comment that it works quite well also. I think you will be pleased with either one, just make sure you purchase the BLACKBERRY version of either.
I use a skin on mine for protection like you mention, like this black one: Gsm Unlock Online-When only the best will Do
Good luck, AND welcome to the Forums.