If you havent already, run a search on the subject. There have been many posts on this subject along with discussion on bar risers. Most of these posts have many pictures which should give you a good idea on what things look like.
That being said, If you use the Powermadd hand guard mounts, and want to use your parking brake, you will have to move your brake lever and switch block inward (toward the center) on the bar so the mount can be placed between the grip and brake block. In order to move the brake block inward you will need to remove a welded anti-rotation tab off of the handle bar. You can remove this tab pretty easliy by bending the tab back and forth with pliers then filing the rest of the weld off.
I believe that if you use the Rox mounts you can place them on the inside of the brake block which would be ideal. I didnt go with the Rox mounts because I was cheap.. Here is a picture of my Acerbis hand guards with the Powermadd mounts. G.B.