Found this kit on Amazon. Adding a Rpi 4 to it made an affordable streamer I can use for Spotify Connect, Airplay and my local FLAC files on a USB hard drive. To get Volumio working I set the I2S DAC option to ST400 Dac (PCM5122) - Amp. By default they don't tell you what setting to use in Volumio. I like that the RCA output jacks are on the back with all the other connections.