Perhaps something that mimics the abilities of the swiftblade PrC?
Going in that vein, perhaps as a greater power (probably two synergistic ones, actually), constant
haste effect with the Perpetual Options class feature of the Swiftblade? That would give you constant 3.0-grade
haste, and given that you should have snagged Cunning, the ability to bring it to bear at all times. Also, if you can integrate other magical items into it, give it the relic power of a Tome of Ancient Lore, for infinite (well...all) arcane spells known.