Check the Media Section of this forum for wallpaper, scroll the threads there, some good ones with lot so images. Media Center - BlackBerryForums.com : Your Number One BlackBerry Community
Applications, see the Aftermarket Software section, and our FAQ, site in my sig below, "Third Party Applications".
i don't know about motorola images, what format they are. Do you know? Why not copy them off on your PC and see what you have. i know jpgs will open on a BB.
Good luck, and welcome to the BBForums.