I saw this thread and realized it was old. What did you finally end up with OP, the Felt and Ibis are awesome bikes and I hope you found a solution. Some of the replies here were ludicrous. I actually use one of these:
http://www.rei.com/product/722143 which works fine and no scratches so far. I've got a Fisher 29er large frame and it fits well. I wouldn't carry more than 1 bike at a time though.