Some of the Turbo Squid stuff looks affordable for the sun, I will just have to come up with something for the moon.  Thanks for the tips and if you come up with anything else let me know.  I do have some 3D planet models I can use, a high degree of realism in this case isn't desireable because it's a scene with toon characters.  I used to have the sun thing for emotiguy, but I don't know where it got to.