This took multiple hours. With over 50 layers/effects and such and a ton of blending, text, etc. it was really hard! It's available in 1680x1050, 1440x900, and 1280x1024. 1600x1200 would work too, you would just have to click "stretch" when you tried to apply the 1680x1050 version, it would be very slightly lower quality but you probably couldn't notice.
The 1680x1050 version is on a different host as it is ever so slightly above Imageshack's 1.53 MB limit.