its the zamorak book from the quest,uhm i dont remeber the quest now,its like horror form the deep i think,and it brings up all your attack bonus's,while the sara version brings up defence,and the guthix version brings upp both a little
Unholy book and guthix book (i think its called book of balance can't remember) Both give range attack bonuses, unholy gives double what guthix does though.
unholy is if you're not tanking, but if you want def bonuses the book doesn't have any. Spirit shelid is the way to go- it has no negative bonuses and is cheap, slightly better than rune kite.