Our couch is against the back wall. In our old home, I had the surrounds mounted a few feet above ear level facing each other. I was looking at the Polk Audio RM201's. They have a small stand and I could put these on our 2 end tables, but they would be right at ear level. Would this sound okay, or should I mount them on the wall higher up (facing each other). ?

Preferred to be above ear level. It certainly doesn't cost you anything to try them on the end tables at ear level and see how it sounds to you. The difference may not be deemed significant by you, or you may even decide you prefer it.

Note that the above-ear level applies for HT. You actually want them at ear level if you do multichannel music listening. So if you do a lot of that, the ear level placement may actually be preferred.

So just play around with placement and see what sounds best to you, or what is the best compromise for you aesthetically etc.

According to Dolby labs and THX the proper height for surround speakers is 3-4 feet above the listeners ear level in the sitting position.

I actually prefer my surrounds only slightly above ear level, maybe 8 inches to a foot above. I'm using Axiom QS8s, but they just seem more present and have a greater impact at the lower height.