You could always make your own, get a piece of MDF and glue some wet 'n' dry emery paper to each side, 800's and 1200's grit should be ideal.. Check out youtube theres loads of ideas....http://www.youtube.com/watch?v=bTX7rqv7szs
http://www.youtube.com/watch?v=QV8MtMU3Eck