I decided that I would hackintosh my newer latitude and I actually got the installer booted and everything, but no display. Since there's no 100% clear guide, I followed the 6220 guide hoping it would be close enough.
When I boot the installer, it boots up fine, but when it escapes verbose, the screen flashes white, then nothing comes up, although it did boot as the hdd activity light is active.
My 6420 has the 4200m and the 1600x900 screen.