The tempered Ni200 is the only way to go
Even the tempered Ni, just is not as durable as Ti I have Ti coils that last for months! I can pull my wicks real tight with out any issues Only problem is you have to twist up your own Ti Claptons
If Ni80 is 80% Nickel why wouldn't it be able to do TC? I have these Ni80 Claptons I got on FT for Dirt cheep & the flavour is just outstanding! It's really too bad they aren't TC compadable