I used to build a lot of military planes as a kid. Lately I've been building F1 cars and GP bikes. Almost all Tamiya kits which are very detailed. What you can't find in SL you probably can find on e-bay. There are full kits with paint, cutting blades and other supplies that you need to complete a plastic kit.
Little tip, use ladies finger nail file as sand paper. You'll have lot more control over what you're doing especially on tight small area and a tooth pick to apply paint on small areas.
This was my last project.
http://s228.photobucket.com/albums/ee38/Mani-1/RCV%20211/
http://s228.photobucket.com/albums/ee38/Mani-1/Die%20cast%20cars/