Re Expanded spellbook: I'd drop it and make it a priority to get Tome implements instead -- as every Tome you own adds two daily spells if its level or lower to your spellbook -and- lets you use the tome (as a daily power) to trade out one of the powers you prepared for the one in the Tome. (even if you then use the power with your primary implement). Same (better) effect -and- lets you actually use the extra powers (twice per day, at that, as you can prepare it and also use the Tome daily to gain access to it a second time at need).