I've been looking around a while too for the white mage sprite from FF: Origins.
Best (and only) place I've seen a good picture is from the game guide for FF: Origins itself. If you want me to I can try to scan that page and post it on the web for you (but it woud be prolly Monday-- my digital camera is with my friend at her brother's graduation- pray it survives the ordeal).
Also, you could try digging around the screen shots of GameSpot.com.. they should have some.. but I think most screens contain the warrior, theif, white mage, and black mage...
Hope that helps any