I will second the Godox recommend. Other options include Pocketwizards or using another Nikon speedlight with commander functionality.
I use the SU-800 with Pocketwizards which works very well. Using the SU-800 by itself works fine but I ran into two problems with it. First you have have to have line of sight if there are no surfaces to bounce off of. And in really bright light it can have problems triggering speedlights. Both of these are really specialized situations.
Lastly, if you want a great guide to using Nikon CLS I recommend the following book:
Comments
https://www.ebay.co.uk/itm/Godox-X1N-i-TTL-HSS-2-4G-Wireless-Transmitter-Receiver-Flash-Trigger-for-Nikon/221945143376?epid=1961625879&hash=item33acf62050:g:hNEAAOSwBOtY~ymz
I use the SU-800 with Pocketwizards which works very well. Using the SU-800 by itself works fine but I ran into two problems with it. First you have have to have line of sight if there are no surfaces to bounce off of. And in really bright light it can have problems triggering speedlights. Both of these are really specialized situations.
Lastly, if you want a great guide to using Nikon CLS I recommend the following book:
The Nikon Creative Lighting System by Mike Hagen