After improving my FAS loadout (it had some legacy mods still and I finally got the mats to mod some hull reinforcements rather than using MA hull reinforcements) I went to Byeru Bese and have seen the full range of NHSS there, from Threat 3 to 9. Threat 8 seems to be the most common, then Threat 4, at least that was what I was getting.Just docked at Garnier Station in Byeru Bese - Acropolis in system - picked up 3, 6 and 8 NHSS's on way in (toasted the scouts in the 3).
edit - Now at Lasswitz Port in Atroco - lots of NHSS 4's here - saw several 9's in Veja Manto enroute to here from Byeru Bese - might be worth alook if your hunting bigger game.