Steps are there to break up the boundary layer and introduce air disturbance into the flow along the wetted surface, reducing drag. Sounds like Mr. Salesman didn't know what he was talking about. I wouldn't worry too much about the lack of steps in the smaller hull. With decent HP, the hull will lift enough so that only the last couple of feet will be in contact with the water. Most steps are well forward of that point and wouldn't be doing any good at top speed.
There are a couple of guys on the boards here that have 22 Sportcats. Craig and Tee could probably answer any questions that you might have.
-brian