S8050 and S8550 are "obscure" transistors in my opinion, why use those?
They will probably just work though, their Hfe is > 100 and usually that's all that matters in such a low power circuit.
But looking at the schematic (of which you should include the picture, not just a link) I think almost any general purpose NPN/PNP will work.
I'd use BC547(NPN) and BC557(PNP) but that's because I have plenty of them (as do many other hobbyists). If you're in US you might choose 2N3905(NPN) and 2N3906(PNP) instead.
But really: it does not matter much, the circuit does not rely on "special properties" of specific transistors.