If you choose a ring (say, a ring of feather falling), you can always add other enhancements over time. When you can afford it, turn it into a ring of counterspells/feather falling, and then a ring of wizardry I/counterspells/feather falling, and so on.
Or you could try a hand of the mage (making it a creepy intelligent undead claw). Perfect for a necromancer-type. Especially good if you can give it some way to move on its own.