Was there a quality issue with the transistors themselves or with the amplifier design? The 2SD555 and 2SB600 look like an ordinary (but old) high power complementary pair. As noted on many web sites the MJ15022-MJ15025 family look like they exceed the specifications. Other suggestions are made for using MJ21193-MJ21196 which also look good.
Are you confused that many different transistors look suitable? It's not uncommon, because for the most part you're just trying to exceed the ratings of the original 1970's transistors. Check voltage and current rating, gain, and bandwidth.
Plenty of voltage and current rating is good. For gain and bandwidth, you shouldn't have too much or too little. Second breakdown performance is new since the 1970's, and could be why the old devices had a bad rep.