I have no experience with your amp but ERS cloth can be hit or miss. It requires experimentation. Sometimes I have achieved little or no effect, others times improvement and othertimes a negative effect.
If used inside a chassis, you would need to secure it somehow. Since it is conductive, you need to be careful about situtations where it could produce a short. If you get the adhesive backed cloth, it can be difficult to remove and may leave the adhesive behind.
I suggest you find a way to keep the amp away from the other components even if only resting it on a thick book on top of a component.
You may wish to consider tweaks such as PowerWraps RFI dampers on the power cords for the PVR and player. I have found that these help wherever I have used them. These do not filter the highs like ferrite clamps or carbon - they just remove hashy treble crud. You can easily adjust the effect by sliding the device along the powercord or using multiples. They won't do anything for hum though.
Bob