Just bought a Nikon speedlight Sb600 am i right in thinking that if i buy the Sb800 it will act as a remote commander for the Sb 600
or do i need to buy the su-800 wireless commander

done a google but i am getting mixed messages from the tech specs on the flash

any help would be appreciated 

cheers chris

You can use the SB-800 as a commander for the SB-600, and you can also use the SB-800 as an on-camera flash whilst using it as a commander.

It needs line of sight though, and in my experience, it's a bit of a pain in the arse out in the open. I managed for a few years with it though, so it's certainly workable.