I added date syrup to coffee for a few days when I had run out of raw cane sugar. Quite pleasant, I am not sure date seeds would do anything. Go for Chicory if you want an additive.
Carob "coffee" is another fake coffee. As a chocolate alternative it's revolting. However, I have never been desperate enough to try it as a coffee alternative.
Chicory on the other hand is great in Camp Coffee...