DO NOT allow them to put it in a silent auction! Require them to sell raffle tickets for it. This is because it is likely to raise *much* more money in a good raffle than in a silent auction, especially in the current economy. Unless they have deep-pocket money "angels" at the silent auction, you are very likely to be disappointed in how much is raised from all your hard work. There have been several threads about this in the past. In one case the charity was miffed that the quilter required them to raffle her donation rather than place it in the silent auction -- until it raised more money than all of the silent auction entries combined!
Of course, a raffle has to be legal in their state, so that has to be checked out.