Do you have a photo?I know you're looking at a 42", but a 32" lines up perfectly with the factory mount plates on the front cross tube, and makes for a very sturdy install. Depending on how that tube is turned, it can be used to mount the light on the roof top, or under the visor. I have mine under the visor. You can see it in my build thread link, at the bottom of this post.
This is the best one I have at the moment...Do you have a photo?