Building a Grey Knights Army

I have been wanting to make a Grey Knights army for a while, and I was wondering what would be a good force to go with? I have been told the combat patrol is pretty good for them, and getting 2 of them isn’t a bad idea.

With two combat patrols I would have; 2x Brotherhood Librarians 2x brotherhood terminator squads 2x strike squads 2x nemesis dreadnoughts

That equals out to 1300/2000 pts. What would be a good use of the other 700? Some tanks, or maybe more terminators? Or a proper warlord?