Of the ones I can make a judgement about, in no particular order:
Tier S: Prog 46, LT-432, EBR, Bourrasque
Tier A: Defender/52tp, Skorpion/su130m, 122tm, and maybe t-44-100
And tbh, if you are looking for your first tier 8 premiums, you should only buy these blatantly overpowered ones. This would also send a message to WG that they are harming their other t8 premium sales by making overpowered prems.