Help picking an amplifier

Hey guys!

Had posted something similar before, but looking into finally adding a power amp. Setup below:

Martanz 7011 AVR
Martin Logan Ethos (fronts)
Martin Logan Motif X (center)
Martin Logan Motion 40 (rears)
Martin Logan Dynamo 1500 (sub)
My cabling will all be improved soon - but I have upgraded power cords on Ethos and Marantz

Obviously, I'm a fan of ML. I like the warm sound of the electrostat and Marantz combo, so I want to find something that will compliment them. Where I'm torn - should I get a 5 channel power amp, or would a 3 channel serve me well? I do watch a lot of movies/PS4, but the rears don't get used all that much anyways. I was thinking to save a little $$$, I could get a 3 channel to power just the fronts. 

I know that electrostats are tricky, and I have been told to try out several amps. I think I have narrowed it down:

Rotel RMB-1575 (there's a great deal on one here)
Anthem MCA 325
Parasound A31

There could be others, but I know people have spoken highly of all of them. This will be my first amp, so I want to make sure I get something "decent" - doesn't have to be super pricey, as I would rather wait until I move houses to get into really high end stuff. 

I'm a newbie on the audio side, I've always been more into the video stuff. Thanks in advance for any help/guidance/input!