The Sziklai driver transistor has the full output voltage on its collector, so it has the same Early effect as if it was not a Sziklai but a single transistor instead.
So you will feed that riaa network with current not voltage?
If you want super high output impedance, you can always put a cascode bootstrapped to the emitter...
If you want super high output impedance, you can always put a cascode bootstrapped to the emitter...