Do you care about the electrical side of the motor (like current, voltage, etc), or you just need the motor as a source for mechanical power?
There are many pre-built motor blocks in Simscape Electrical add-on library that allow you to model the electrical-mechanical power conversion. If you plan to use those, you probably need to do a parameter estimation exercise so the model behaves like what the dyno curves describe. If the unknown parameter set is large, you may need help from the Simulink Design Optimization toolbox.
If it's just a source for mechanical power, a torque souce and a lookup table may be enough. You can place sensors to measure the shaft velocity, send it to the lookup table that contains the dyno curve info, and the table output would be the torque signal that can sent to the torque source.
So, the "best" way depends on what you want the model to do. More information on that would be helpful.
