I would set up for Atmos, I think.
Keep in mind, depending on the space, you can wall mount them, left and right, at the Top-Front and Top-Back locations with good success.
Most seem to agree that you get more bang for the buck with Tops rather than Heights.
I am weighing my upgrade path along these lines as well.
I could keep my high-mounted Rears and do Top Middle with Front Height, (I think).
Or I could do Front and Back Height as a 5.x.4...
I could get rid of the high mounted Rears altogether and successfully install Top Front and Top Backm again as a 5.x.4... though I do have a way to install a Rear Center instead or Rear Surrounds...
My space gets complicated!
I share because at the end of the day, we all have to take our spaces into account, and very rare is the situation when a person is custom building a perfect scenario with no compromise. How well you navigate the compromise is the measure of success for most of us!