In tc mode its not the resistance that matters, its the coefficient of the wire, or more simply how the wire changes resistance as it heats and cools. This tiny fluctuation is what is being monitored, and is why tc requires a very low resistance. While it should be close, changes in metal chemistry can change the coefficient and maybe make it harder to dial in just perfect,
mods like the dicodes let you enter a coefficient number if you know it letting you use any wire you like.
In any case.
www.amazon.com/Artistic-Wire-Gauge-Stainless-Steel/dp/B0063DH7KE
a good starting point.