A short comment on the problem formulation first.
The term impedance matching is usually referring to passive circuits. A transistor can act as a buffer amplifier with high (ideally infinite) input impedance.
While an impedance matching circuit tries to transform an available signal energy to a different impedance level with low loss, an ideal high input impedance amplifier tries to absorb as little signal energy as possible.
To allow a better understanding of the problem, can you describe the nature of the high source impedance?