I know I'm being a bit evil suggesting this but it'd be awesome:
It's much easier to levitate a magnet from above it so... how about upping the challenge by flipping everything over! You'd need more than one electromagnet to stabilize things. Say, 4-8 coils arranged in a geometric pattern. This also has the bonus of allowing the system to intentionally move the magnet around. Imagine how impressed your family and friends will be seeing a magnet run a figure 8 in the air.