Inverto Black Pro C120 LNB is certaily best for My Prime Focus 2m Dish .
Inverto Black ULTRA 0.2db LNB and/or Golden Interstar Single LNB 0.1dB for any Offset Dishes
i tested many LNB's on my 1.2M offset dish and found Golden Interstar to be the very best with preformance
i dont get such results with using Feedhorn and Inverto Black Pro C120 LNB on my 1.2M Dish
but ive not really played about and tested with it much
this i will do in coming days aswell as test a C Band LNB aswell something ive been wanting to do for a year or so
TM5402 M3 HD is good can find feeds with low SR too
my TBS 5980 Q-Box always been good for feeds like this aswell with low SR
Bigger dish sure will help but good LNB can make a decent difference too , any good 0.2db LNB always gives better results than 0.3db or higher .