Specialized makes some very nice non-compressible forefoot lifts/shims that go inside the shoe. Unless you already have orthotics that you want made into full-foot, I'd be looking at the Specialized goodies.

(If you already have orthotics, your Orthotist will know the lift at your heel and should have no problem just *giving* you a slab of cork the same thickness for your forefoot in the bike shoe.)