So, I got 2 covers:
the first, this one
http://www.ebay.it/itm/BOOK-LEATHER-...b232968&_uhb=1

in black
I was pleased but the autosleep (it wasn't publicized though) wasn't working, the magnet was there though so I cut a square over it, on the "pocket". Anyway, it was doing its job after but overall it didn't look sturdy enough to properly protect my aura hd on my bag, so I wasn't actually taking it outside!
The styli, though, is great. I use it all the time when I'm home and my hands are dirty because I'm cooking or have cream on them. Really useful.
then a few days ago I got this one from amazon
http://www.amazon.it/gp/product/B00E...?ie=UTF8&psc=1
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in blue.
I got this one and I'm a bit in love XD Its front is a lot sturdier, I'm now less anxious and taking my kobo outside with me. The back follows the kobo uneven back and it's very cool and hard, too. The autosleep functions perfectly and the magnet for the closure is great, too: not too strong that I have to tear apart the cover to open it and not too weak that it opens accidentally. The color is very nice and the kobo fits the cover perfectly. I didn't have to force it nor I'm afraid it can slip out. It is slightly more slippery than the first leather one, but not that much (and certainly not as much as the kobo itself). The quality was high, no weird materials stuck on it or anything.
I'm keeping this second one as my main cover and the first one as backup.