These are my choices based on what I have:
.cellos -
Amadeus - $149 - free Kontakt player - https://sonicscores.com/amadeus/.slide guitar for rock.
no idea other than for the full version of Kontakt.horns eg trumpets.
Amadeusflutes/whistles
Maybe Kontakt player - don't know for sure
Mine are all for the full version of Kontakt.clarinets
Amadeus other wind instruments eg oboes/bassoons
Amadeus .latin perc
no idea except for the full version of Kontakt.violin groups
Amadeus .good rok saxes. i can use some rt but after lots of edit work/regens.
VG instruments - $76 or less
https://vgtrumpet.com/
Not as good as Swam's $250 but a lot cheaper
https://audiomodeling.com/swam-engine/solo-woodwinds/swam-saxophones/.ditto above for harmonicas.
No idea - I'm looking for a good one myself.femme opera and rok back up vocs.(already mentioned in earlier posts)
Amadeus .stand up bass
Amplesound - $149 -https://www.amplesound.net/en/pro-pd.asp?id=21
Maybe Kontakt player - don't know for sure.rok choirs
no idea.other orchestral/symphonic instruments usefull in rok songs.
Amadeus
Maybe Kontakt player - don't know for sure