Jesus or Jihad? GWB in '04.
William Marina might make good use of his post below on possible Bush/Cheney bumper stickerss to make actual Bush/Cheney posters.
The Bush campaign's website offers users a handy function that allows you to make your own, quasi-official campaign sign. They've put in some filtering software to weed out troublemakers, but that just means you'll need to get creative in your tomfoolery.
The ever-loveable, ever-readable Wonkette has more slogan possibilities, as well as suggestions on how to get around the filter. Just scroll down to the relevant posts.