Dave,
If you want to convert it, you're welcome to this Viper model.
http://www.cylon.org/images/bg/joyri...finalsmweb.jpg
Its actually just giving you your own model back. I think I started with the model you have there, stripped it down, and then tossed a few things onto it.
Its in LW but you're welcome to it if you want to try to convert it.
When you start getting more final on this, I think you need a stronger key light to show off the details a bit more. The ambient settings you have make it a bit too washed out. I'd also set the fog back a bit or layer in the grass in the foreground in post so you get a better feeling of depth. I'd even go as far as to add some noise on the hills to make them a bit more defined and then blur them in PS. I'd then load that as my background and render the bulk of the scene and then add the foreground grass last.
Sandy