Order continuous nitinol super elastic wire in any continuous length of your choosing. 

Most people use Regular temperature wire, it will have the best performance and strength (not kink, etc) at room temperatures and above.

If the wire is to be used in a cold environment, you may consider the 'Low Temp' or the 'Ultra Low Temp' wire which is stiffer at room temperature, but more easily deformed because its super-elasticity is more suited for below freezing applications.