I don't know if you're still looking for artwork, but if you are I surely hope this helps...
Here's a customer banner, 800x90 (as specified):
And a custom logo, a 500x500 .png file with a transparent background, that you can re-size and use as you want:
I make no claims to copyright, but if you'd like to credit me, I'd appreciate it. My website (still under construction, but up and running soon) is dccreativestudios.com, and my e-mail is Doug@dccreativestudios.com
If you have any problems downloading the graphics, please let me know and I'll send you the files via regular e-mail.