It takes some effort if you want quality sound in Linux. Setting up JACK, pulse audio sink and Calf type plugins. Then routing the audio through the plugins alll the way to the soundcard.
Therefor I wonder if this can be made into a product using the Raspberry Pi. If the processing power is not enough on the Pi. Than a laptop could perhaps act as an audio streamer. That is. You have a dsp ?server program on the laptop and remotely control it with the raspberry pi over wifi to the amplifier.
If there exists JACK routing over a wifi network? Then all you need is a VNC connection to the PI to solve this project.