There is a way to get model thumbnails, here is the correct format: http://www.roblox.com/Thumbs/Asset.ashx?width=110&height=110&assetId=[model id here, no brackets]
If you want to get a picture of a model without uploading it then you can use a ViewportFrame, read about how to use it here.
Additionally you can just CFrame the model in front of the camera and update it on RenderStep.