Best way to find out if you have a good clean shot at a satellite is to use this web site
http://www.dishpointer.com/ Can drill right in to your address with google maps satellite view and overlays the direction to the satellite you need to hit. It'll give you the elevation and azimuth, even the LNB skew if it applies. Even if your not about to point the dish yourself at least you have an idea if you can install one before making any phone calls. They even have a smart phone app you can download for free if you want to use it.
