I'm not familiar with the models myself, but since they are GW there is not much I see wrong with their use.
Of course if size is an issue we won't know till we can get a look at them. If ya could post a pic or give us a link to get an idea of the model we are dealing with it would be greatly appreciated. But, as stated before, since they are GW in origin I really can not imagine they would be unacceptable. Un;ess the painting is terrible and knowing the way you guys go at painting I find that highly unlikely.