I added a 120W ebay LED bar onto our -X900. I have the metal roof and glass versa-cab windshield. The roof already had two holes drilled, so I fabbed up a mount using some 3/4" square tubing - basically added a couple of tabs to mount the lightbar to, then used the factory roof holes to bolt thru the 3/4" square tube. This put the light bar far enough forward to clear the window when tilted out, but still mostly under the roof overhang.
Could have easily gone with a larger bar, but this is plenty for me at the time - mainly to get some light over the plow, which blocks the stock headlights.