You have not mentioned which AVR you own. You should look through the manual and see what speaker setups are supported. If you can't install in-ceiling ATMOS, then I would opt for height speakers. If the surround speakers are 3 or 4 ft over your head, are you able to move them closer to ear height? If not, then front height speakers might be the best option as the current surrounds are on the high side and might interfere with any height speakers mounted ceiling level.
I had my surrounds in the ceiling originally, facing down (I also have the couch against the back wall). It was ok, but you can't do ATMOS with them there. I moved them down to ear level on either end of the couch and the base layer is now much improved and I was able to add a couple of ATMOS speakers. I believe that Auro3D setups allow for angled height speakers to be placed on the side walls but front or rear height is more typical.