But you can trigger them through CLS and the built in on camera flash?
Yes. Here is an article that talks about this very subject: http://dpanswers.com/content/nikon_flash_models.php
I believe there have even been some additional Yongnuo flashes released recently that are compatible with Nikon CLS as well. As remote flashes, not sure if any would work as commander flashes. I believe the YN550EX is one of the new ones. Not sure what others. Lately it seems Yongnuo is introducing a new flash or trigger every other day! Tough to keep up with all of them as they have similar sounding model numbers and they're all the way over in China. Hard to get any concrete info on what does what and so on. I think eBay and Amazon have been the typical places to find these flashes for sale. I would say do your research before buying and be sure to be thorough! Once you are narrowed down to a flash or two you're mulling over, check YouTube and other online forums/sites for hands on reviews! Good luck. Be sure and keep us posted. My flashes are set to arrive this week!