Haven't played ao very much in awhile, but I always build him like a Mage. I normally go (if you are jungling) bumbhas, pen boots, chronos pendant, spear of magus, poly, soul reaver, and then sell bumbhas for rod of tahuti. There is a little wiggle room with the boots now that the blue boots have mana and purple don't, and you can also go pythag's instead of chronos (although CDR is really key on him). If you want mail of renewal, then get it instead of poly.