I've made three panoramic sceneries, you can download it on
www.rc-sim.de in FMS / 8.X versions / scenes
Their name are "Field", "Schliersee" , "Arzier" and its addon "Add on fuor Arzier" wich permit to crash your models in trees.
Other people have made another panoramic sceneries on rc-sim so you have a big choice.
Personnally I've made my sceneries using a virtual box and pictures applied on it.