Actually, I own a 14" iBook and it works great...very easy to tote around, longer battery life than a 12" model, easier to see what's on the screen too. I bought it as a cheap mobile solution, wound up using it as a desktop replacement. Works fine for both situations, and mine is an older G3 model. Most of the work done on it is in Photoshop, InDesign, BBEdit, Fireworks, etc..
Durability wise, the iBooks will take more bumps, hits, drops, etc. and keep going. They're designed for that kind of abuse.
The downside is the resolution for the screen. 1024x768 is a bit smaller than I'd prefer. Then again anything larger than that on a 12" screen starts to become too small.
If the superdrive isn't something you absolutely have to have, consider a 15" PowerBook with the combo drive. It's still very easy to tote around and might be a better size for what you're intending to do.
Best bet is to go to an Apple Store/reseller and play with them all, see what YOU like the best.