I bought the following cover from Amazon ($16.99 plus shipping). It has a built in Keyboard and a USB cable (but you need to buy an USB extension cable to reach the top of the Edge PE).
An open PE fits neatly & securely in the top of the folder.
The keyboard works fine (it even has lights for Num Lock & Caps Lock). I still haven’t figured out all the key combinations but F4 rotates the screen.
10.2" Synthetic Leather Case with Keyboard
ASIN: B004JQN670
http://www.amazon.com/gp/product/B004JQN670