One thing to be aware of: the LR load is in many ways quite different to a motor load. Obviously you'd start with inductance equal to the motor inductance. But the resistance is tricky...
For equivalent power, you can use a larger value resistor to dissipate the appropriate power (V*I). However, this arrangement has a high R to L ratio and will therefore be well damped and well behaved. It's OK for power testing and very crude current loop testing. It offers no Back-EMF (BEMF) signal.
To get realistic current dynamics, the L and R values should roughly equal the motor windings. This might well be covered by the inductors' internal resistance. This arrangement should have a more realistic current dynamic, but will be totally wrong in terms of average voltage and power dissipation. It offers no back EMF. On the plus side, it won't dissipate a lot of power.
If you have money to spend, you can get power simulator electronics systems which have a power converter (looks much like your motor driver) with special controls that pretend to be a motor. This will offer pretty good current dynamics, pretty fair power flows, some kind of back EMF waveform and some nice features like to ability to model a mechanical load.
The real acid test is of course to use a real motor connected to some kind of dynamometer (traditionally a separately-excited DC machine). This offers the true behaviour: saturation, back EMF, resistance change with temperature etc. It's a bit irksome to set up (needs stiff base, mechanics, guards, some kind of load controller for the dynamometer etc.) but can be very effective.