IMO you need both overhead and task lighting in an office so bite the bullet and do it right.

You could install on the ceiling even if there's not a j-box, I've seen many homes and condos where there's lighting on the ceiling and connected like a swag fixture (long cord to an existing wall outlet).

If interested I do make custom lighting based on the client's specifications.

Feel free to request a no-cost quote at: Retro Steam Works / Custom Lighting Design

PS. I did that on my son's room, where we installed a chandelier and connected it to a wall outlet (controlled by a wall switch).

If you decided on a chandelier there are many options on this website: http://woodenchandeliersplus.com