Well what I can tell you, is one create you UI elements in photophop, I like to desgin how everything will be placed in my design resolution, once am happy with this layout I just save the psd file then pop open CS. CS isn’t that stable yet, that is why I do alot of my work in photohop, I import the psd file, now I can add my UI elements, I also convert my layers to smart objects before I save my psd this helps when importing and also when exporting from photoshop to larger resolutions.
Now you can just create a button using your UI element created from photoshop and add a label/Atlas as child to it with what text you desire.
For mult-res, What I did was just export my assets to larger resolutions and copy the entire CS exported folder to HD folder. So design in 480x320, just change the assets resolutions to whatever multiple.
Hope that helps