Slim Line Antenna Mount

I am in the process of a new home build. I intend to purchase the DirectTV Whole Home DVR + HD service. From the forum it appears I will receive the SWM slim line antenna. The house will have a tile roof. I want to build a custom antenna mount on the roof that is easily accessible for installation and will allow the antenna to simply bolt to a flat plate on my mount. The mount will penetrate the roof and bolt directly to my roof trusses so strengh and stability should not be an issue. What are the dimensions and hole locations of the antenna base/mount so I can build a plate the installer just has to bolt the antenna to? Is there a diagram or print available?

Thanks