Herrschner's carries a wide variety of crochet thread, but I would ask the hookers on Rav for comparisons with embroidery floss as I'm inexperienced working with crochet threads (I'm still trying to figure out the sizing conventions, much less fiber sheen!).
http://www.herrschners.com/dept/Crochet+Thread.aspx

You could also try Nordic Needle - they carry a ridiculous number of fibers.
http://www.nordicneedle.com/CTGY/thread.html

I have a hard copy catalog from both of them if that would be easier on your brain.