I've ordered from Cummins Nursery in the past and they seem to have a pretty good selection of cider apples. Here is a direct link to their cider page. While Cummins does offer a good product, they are a bit on the spendy side ($21 a tree when ordering 50-99 trees). It's very late in the season for ordering bareroot trees, so I would expect most places to have a lousy selection if you are ordering for this year.