Change eye colour? Easy.
If you've seen the level 17 cutscene in Eureka, you'd know that Lupin are only really 'furry' around their heads. While still furry around their chest, you can actually see their muscles.
Probably borrow some from Miqo'te and Roegadyn (Au Ra males have a few Roegadyn voices, if I recall) as well as some new voices
Telling the difference between the genders is where it'll be tricky, unless they have a few different features to set them apart from the males (that do NOT make the females more human in appearance like some games tend to do)
Hairstyles is another thing.