2n3906, 2n5087, mps6562, BC327 are all good Si pnp bjts. Ge will work also, with the usual caveats (leakage, temperature instability, etc.)
There are a couple of different ways to convert a circuit for pnps. If you're willing to use a battery or a dedicated (non-daisy-chained) adapter, then compare these two circuits and modify yours similarly.
If you want to use a daisy-chained adapter, then there are at least two common ways to modify the circuit, neither one is 100% successful for reasons only the gods understand. I usually recommend leaving the circuit as positive ground and building a dc inverter into the pedal.