I've been working with EB for almost a year now. Here's my very best advice. Go to their FB and look in the photos sections. Check out the three latest albums, #18, 19, and 20. Find pictures that you like and ages that you need.
The model's names will be under the pictures. Request those girls. You've already seen their picture quality so there won't be any surprises.
Your other option is to use one of the photographers that work through Ellie Beans. You won't have a clue what the child looks like but these are all professional photographers who will use your stuff on their next shoot.
You cannot go by the comp cards! All or most of them are professional, the pictures you get back won't necessarily be.
Overall, you should have a great experience!