Actually, if you want to take a loot at an interesting way to handle cyberware, take a look at the latest Dungeon/Polyhedron.
The Polyhedron setting for this issue is Mechwarrior/Batteltech stuff -- which is cool enough as it is, but I really like the way it handles cybernetics -- not as something you buy, although you can roleplay that -- but as a class -- characters with cybernetic implants take levels in Cyborg, a advanced/prestige class. Additional levels provide bigger and better options for cybernetic enhancements.
As or magic . . . that's one of the really, really cool things about the Shadowrun system. The idea that you don't have spell points at all, but have to resist drain based on the strength of the spell you cast . . . that always struck me as the coolest magic system out there.
BUT you could cobble together something for D20 pretty quickly. Use the base Sorcerer class -- but rather than giving them a number of spells per day, only use the spells know. Then, every time they cast a spell the sorcerer has to make a Spellcraft roll to resist the drain of the spell. The Roll would be DC 10 + spell level +caster level -- so a first level spell cast at first level would be DC 12, and a Third level spell cast at 5th level would be DC 18.
If they resist they take no stun, and can cast again. If they fail, they take subdual damage equal to caster level + spell level.
That's quick, but it just might work.
-rg