I vote for the "Idea" of poster 26, so I picked #26, but the most eye catching poster is #20, as that bunny is adorable.
The idea of Poster #26, having the rabbit at the background, and yet you still have the space on the foreground is brilliant.
I'll go w/ the poster of #20 using the idea of #26, that way, you can fit more words on the poster.
A few things:
1) because the name of our web site is so long, we should use capital on the final poster, I notice some posters has it, and some don't. i.e., "RabbitRehome.org.uk" instead of "rabbitrehome.org.uk"
2) "Can you offer a permanent, loving home for a rabbit" is too long. Over here locally in the SPCA, they use a very brilliant line "Will love for food", and that line in conjunction w/ a adorable looking rabbit, like poster #20 speaks volume