From your provided list of choices, I would recommend the 85mm f1.8. It's a great lens that would have a similar FOV as a 135mm on a FF camera. Good for headshots. After that, I think you are set with your nikkor. I typically view 50mm-135mm as the portrait lens range, but on a crop that would be around 35-85mm.
If you are happy with your 50mm, you may want to think about a 35mm F2.0 IS. I don't own one, but I've read that it's a good lens for the money and would fill any need for a full body photograph without having to backup as far.
I also have used the 60mm 2.8 macro for headshots. It's a very sharp lens for crops, but may not offer any advantage over the 50mm you already own.
And, as previously stated, the 24-70 2.8 mk II is a great lens (if you aren't looking for faster than 2.
if you would rather have 1 lens than a handful of them.
Last, if you are shooting over f4.0, then there also is the 24-105L. I've got that one too and you can find them at good prices if you shop around. I would recommend the 24-70 over this lens if money is not an issue, but this lens does produce some nice images.