You can try any npn with hfe over 500. BC547/548/549/550 from the C series shoud do the trick, but only the 550 has the same noise figure of the 5088. Another sub is the BC169, you can even try a bc108/109C. Other than that, you can go the nte way, but those parts are expensive and with more *random* specs. I´m not familiar with 2SBxxxx transistors, but you should find some equivalent to the ´88.
Edit: The BC237/238/239 series is also usable.
From the faq: "From R.G.Keen:
2N5089 will work in most instances. Also useful are 2N5210, 2N4401, BC549."