XF86Setup is (or was last time that I used it) a text-based system that lets you modify the XF86Config file without actually changing the file. When you run it it will detect/request your hardware and let you make changes. Then when you finish, it will save it back to the XF86Config file.
OR
Run "Xconfigurator -kickstart" and hopefully if your hardware isn't too weird it will automatically set it up for you. The first method is more full-proof than this one. Using "-kickstart" you are hoping that it will detect everything correctly for you.
When you are done you'll need to restart X and then cntl-alt-+ should work. The issue appears to be that there's only one entry in your XF86Config file, so when you are changing it, it's just flipping through the same one over and over. If you add additional entries, it should enable you to flip through them with the cntl-alt-+ method.