A:
The N750 will be a good choice. But satellite internet is sometimes a little different than cable/fiber optic. In other words, after you hook up the N750 and your connection speed plummets... It may not be the router.
Call DirectTV to verify that you have the proper equipment in your house to begin with before buying any routers. Once they confirm that you are already properly configured, then you should be able to purchase the N750 and set it up with no problem.
Otherwise, take the advice of DirectTV as far as what to purchase.