swapping the dish on top to the winguard t4,motion

As long as you can switch to Dish later....from all reports Direct TV won't be supporting Standard Definition Receivers much longer. Dish may not be too far behind on Standard Def. I have two older Dishes on my RV, an in motion and a real old Datron system, both Direct TV standard....so I see upgrades or service change in my future. The T-4 is not cheap...so buy carefully.