I do indeed intend to pay an artist, up front. Thanks so much for your informative answer!

You're very welcome and thanks for the shroom.

And to your other Q, yes, screenplay-style is preferred over a novella by *most* artists, but again they're all different. Like I said, some really appreciate rich deep text to work from, whereas some want to bring their creativity a good challenge (Warren Ellis does a painfully minimalistic script for freakangels.com that he's kind enough to link to at the bottom of each art page).

As far as finding someone, online forums are good (also check out shaneglines.net, http://www.deviantart.com/ , http://www.drawingboard.org/ , http://www.webcomicz.com/forums/ dayfreepress: http://www.samandfuzzy.com/links.php , http://forums.penny-arcade.com/forumdisplay.php?f=14 , etc etc ) and you can also try the direct approach - email artists who have made work you like, and ask if they do commission work. Then ask if they'd take on a long-term commission project. I approached a few of my favorite artists this way with one of my novels, and actually got a bite from one... whereas another (a local artist) declined, but she gave me the valuable and logical advice I passed on to you in #2, above. There are a variety of payment schemes that artists prefer, so be prepared to stay loose/limber in that regard. Some want hourly, some want day rates, many want a contracted page rate.

And FFS, please also read this gent's lovely 3 books about the art AND writing craft in 'comics':
http://scottmccloud.com/

Good luck!

Both DC and Marvel have both put out books along the lines of Denny O'Neil's instruction book. All will claim to tell you how to do it, or how Marvel or DC did it. But in addition to reading one of those, I'd encourage you to hang out at your local comic book store, and ask the owner or clerk who they know in the area who would be a promising graphic artist to link up with. You might just find the next up and coming hot property and get famous in the process!