Xpro1 Half Cases
Luigi's cases are the top, but as you mentioned they're really expensive running around US$250. Ouch.
I"ve got them on my M6 and also my Bessa 3A, fantastic stuff. For my M9 I went with Ciesta which I think is also available for the X-Pro1, but on the M9, the leather is a bit thin, it catches parts of the camera when I take it off to access the SD card. Half the price of Luigi's, but other than the price, I don't like it at all.
You mentioned you looking for extra protection on the back, but from the picture it loos like you might have difficulty accessing the buttons on the back of the camera, since the leather punch out holes appear a but tight to my eyes. That would bother the hell out of me.
For myself, I'd rather have very little protection on the back, like say a Gariz style case, than to be fumbling over the buttons.-- hide signature --
M9 X-Pro1 E-M5 X100 DP2
After shipping the Luigi cases are closer to $300. A bit to steep for me. I don't mind not having great access to the buttons on the back. I'm fine shooting without them anyways. One of the reasons I love the Xpro. I can adjust my settings with the manual controls and not have to bother with going through menus.