Recommend a good Smart Cover compatible back cover case: KaysCase Smart Solution
This is a fairly new brand, but they have a huge back case product line for the new iPad. They have soft case, hard shell case, case that is in solid color, and case that is translucent so you can show the Apple logo and the engraving.
The cases are available on Amazon
The price is just $15.99 - $19.99, and if you buy two of those, you get 20% off.
Hard Shell: Amazon.com: KaysCase Smart Solution Hard Shell Smart Cover Compatible Back Cover Case for Apple iPad 3 3rd Generation - The New iPad (Clear): Computers & Accessories
Soft Gel: Amazon.com: KaysCase Smart Solution Soft Gel Smart Cover Compatible Back Cover Case for Apple iPad 3 - the new iPad (Black): Computers & Accessories
KaysCase Smart Solution Hard Shell Smart Cover Compatible Back Case with Magnet Strip
You are probably wondering what that dark strip is on the case. That is a magnet strip taped to the inside of the case, so when you fold the smart cover back to your iPad and read it as a book, the smart cover will be secured to the back of the case and will not flip around. I know some other cases are doing this. For example, the Belkin snap shield secure actually includes a small piece of metal strip on the case. The magnet tape is just a brilliant idea so you can make every back case a magnet secure case.
I also bought the strip from KaysCase on Amazon
Amazon.com: KaysCase Smart Solution Cover Case Magnet Partner for holding Smart Cover to the Case for Apple iPad 3 - the new iPad: Computers & Accessories
I had a little fun cutting out my son's name with the strip. If you buy a KaysCase clear back case and a magnet strip, be creative with it, and upload a photo as a customer comments, they will give you the case for free.
I don't have any pictures without the magnet strip, but the magnet strip is not part of the case. You can take it off and put it back on again. I do not want to do that because it took me forever to get it straight with the name on it, and really don't want to do it again.