How about adding a lightsource separately on the surface of the model you like? If you pay attention to the light power, size and placement/elevation, you should be able to get the desired effect. Then you can group the combination and copy.

ok

PS Imported models will not have a light source included (unless I have missed something in the supported import formats). It is possible to add lightsource properties to any model, but much easier to follow the method outlined above.