Protocol48

I have a 9.2 receiver. I am considering buying the Atmos System: Qty=1 - RP-280 5.1.4 DOLBY ATMOS® System, and maybe a 2nd subwoofer. Q1: Do the RP-140SA Elevation Speakers go on top of the rear speakers? Q1a: Do putting the elevation speakers on top of the rear speakers really add to the sound field? Q2: Are the Qty=4 - RP-240S or RP-250S recommended for for the 6,7,8 and 9 of the 9.1 system? I have seen Klipsch ads where a stand used for the left and right middle speakers. Q3:Does Klipsch have a stand where, on the side speakers, I can attach one of the RP-250s, for example, at ear level and the other significantly above it for the ceiling effect?