Hey, here you go. The huge majority are still white kids, but there are a few good ones of children of color:

http://www.bigstockphoto.com/search.php?q%5Bst%5D=child+children+reading+book+books&queryppn=3&queryprpp=36&queryppin=5

I was expecting there to be more photos to choose from but this is one niche that hasn't been beaten to death yet.

I still think I might advertise at the laundromat for models. If I watch my finances I will have some money every month that I can use to pay them, and hopefully I will make at least some of it back.