I just had the 550 and 559 on hand when I built my units so they ended up in the BOM. I don't see a reason why the others wouldn't work. On a closer look, they don't even match at their collector voltages (550 is 45 volts, 559 is -30).
Mine had the C classification (again, didn't give it much thought) but I don't remember any of those reading much more than 400 hfe on the meter (most were lower). Could have been the meter, though but I think if you grab at least B it'll be fine.
Mine had the C classification (again, didn't give it much thought) but I don't remember any of those reading much more than 400 hfe on the meter (most were lower). Could have been the meter, though but I think if you grab at least B it'll be fine.