ATO includes the main box, the float switch on a hanger, an Aqualifter, and the hanging kit for the aqualifter. My tubing is a little worn so you would probably need to replace that and you'ld need a container for the water.
There is one person ahead of you for the Skimmer. I could do $30 for the ATO and $20 for the skimmer if its still available. I reached out to the guy for a definite yes/no on the skimmer. I'll let you know what he says