Finally decided to start collecting Shana artbooks though these are just doujin lineart books sold at Comiket 69 and 70. Seems like the auction I won it from also threw in a clearfile and illustration card as a bonus.
Also won the Shana II visual book a few days ago.
Now gotta also get the two official Shana artbooks by Noizi Itou (the ones with the black and purple hardcovers).