Surge protection limits current and the last thing you want are sacrificial components to protect against surges. Surge protection will also limit sound quality.
You can't beat a large, big and heavy torroidial transformer. This acts like a reservoir providing conditioned power while adsorbing excess voltage.
I have found Plixir AC and DC power supplies and conditioners to be excellent products, which are balanced in operation.
Plug your power amps directly into the wall, their coils are big enough to protect them.
There is only so much you can do unless you want to spend 10s of 1000s.