Enter your location and you'll find both Viasat-1 and Viasat-2 in the drop down list. Select one, search and then click on the marker that shows - it'll show you elevation and azimuth for the selected satellite (or you'll find the info below the map). There's also a basic line of sight obstacle checker that may help to determine potential LOS issues.
Viasat-1 is at 115.1W, Viasat-2 is at 69.9W
Last I knew Viasat had a 10 degree clearance requirement on all sides.