Kelly's got a lot of great ones.
The background you see there, was made in VMS in less time than it took to render it.
What I recommend is that you buy a half dozen or dozen of the backgrounds from Kelly, Artbeats, Digital Juice, or one of the dozens of smaller websites, and then using compositing, create your own backgrouns. This one uses two backgrounds, a mask, and generated media, thus using all four tracks that VMS offers.