Many motorcycles have "direct drive".

They turn them up to 15K RPM and I have never seen one come apart yet. The weak link seems to be rectifier and regulators, not the stator exploding due to high RPM. The motorcycles use the same Nippendenso "mini size" alternators like you see at the auto swap meets with just a different drive. In fact you might even take a look at one from a late model Triumph so you could adapt the driver instead of converting over from an automotive pulley style. Near as I can tell they look identical.