You can try Pike's Peak or Mussers and see what they have left. They usually have good stock. Just ask about disease resistant ones and ones that hold their apples till late fall. You can plant them anytime in the spring.
And be prepared to make about a 6 X 6 fenced around them or the deer will destroy them.
You still have a pretty long window for planting yet. I don't know if you're looking for a lot of trees or just a few but Mussers up in Indiana has a nice variety. I actually have a couple from wally world ( GASP!
) that are doing very well. One place I'd never buy any kind of fruit tree again is Lowes. I've had several apple trees die for no apparent reason. If you're going for bulk planting I'd go with a reputable nursery.