http://www.compfused.com/directlink/4080/
You have to check this out, it is possibly the coolest RC vehicle I have ever seen.
Cheap Airhogs retail version (https://www.spinmaster.com/product.php?productid=16204&s=storm) not nearly as powerful but probably pretty fun.
Fair amount of info on Digg in the comments section on the different kits out there. (http://digg.com/videos_people/Video_3_in_1_RC_Boat_plane_car)