Powder Orange isos are insane... they are crazy active, crazy fast, and reproduce very quickly. The little buttholes have invaded all my other isopod colonies, and eventually they out-compete the others for food. They are very hungry little guys. I did add some to the enclosures of chameleons that I know actively hunt isopods. I figure they'll keep numbers in check, and their activity makes it fun for the cham to hunt. They don't really leave the soil layer of my enclosures, but I probably would not put them in a smaller enclosure. I could see where they might be tempted to take a nibble on a grown dwelling animal if there were nothing else to eat... but in a bioactive enclosure, there should hopefully be plenty to go around... and so long as its not a small enclosure, there is plenty of room for them to run and climb w/o coming into contact with your chameleon.
I think Giant Canyons are hard to beat. Great CUC, active, decent reproduction w/o being swarmed with them... and they tend to climb around to clean the upper areas, now and then. Zebras are probably my favorite, but they do chew on my plants sometimes.