Putting a sub with a plate amp in the wall can have a lot of problem. If you don't mind a small hole in the wall, the amp can be in another room. They make wall coverings for speaker wire. I agree that the Rythmik sub is a nice one. A lot of other subs also sound very good and would work well for you.
Klipsch RF 7 based HT 7.4, Pioneer SC 35, Acurus 200 Five, Dayton 18 Ultimxa Dual Sub Cab(2), Dayton 18 Ultimax Large Vented Sub Cab (2), on Berhinger I Nuke DPS amps, Samsung BDP F 7500, Asus/My Book Live HPC 4 TB
Yaquin VK 2100 amp, McIntosh XR 5 speakers, Samsung BDP F 7500