If you really do a lot of portraits, you might want to economize on the general lens - perhaps even the kit 24-85 VR - and also get a specific portrait lens, for example the 85/f1.8 AFS. The two together will run considerably less than the 24-70/f2.8. Right now it looks like the kit lens adds about $500 to the price of the D600, and the 85/f1.8 AFS is about $500 also. The 24-70/f2.8 is $1900, so about $900 more than the pair of them put together.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!