I also worked the board for many well known artists visiting concert venues in my area. Just a few to mention a few, chuck mangione, Maynard furgison, and many others.
That is really cool. I was and still am a huge Maynard Ferguson fan. I was the weird kid in grade school/high school who preferred rocking out to Maynard's "MF Horn" albums instead of the popular rock and top 40 artists. His "High Voltage" period is a little cringy, though...
Back to streamers, I'll also recommend the Bluesound Node as a starter. I know you mentioned looking for used. Just an FYI, there is a difference in processors (1 GHz in 2i vs 1.8 GHz with 64-bit support in Node) and a better DAC (192KHz max on 2i vs 384KHz on Node). I can't personally speak to the sonic improvements due to those differences. I own the newer Node model and have only casually listened to the older 2i at my dealer. I'm pleased with the sound. The reviews I've read comparing Node to Node 2i give the nod to the Node because of the better DAC. I will hopefully be getting my new preamp soon with what I believe should be a higher end on-board DAC and am curious to see if using that DAC with the Node makes any discernible difference.