What is best Mac and OS for running iTunes into the future.

My music and audiobooks run on a dedicated late 2009 iMac running High Sierra and iTunes 12.8.3.1. I connect with my vintage stereo with a USB Digital to Audio Converter. My library is 1 Tb and resides on an external FireWire 800 drive. This has worked well for me but it is obviously getting old and connecting to late model iPhones and IPads have started to be come issues. I was thinking that upgrading to a late 2014 Mac Mini might add some years to my Rube Goldberg setup. The key is I’m trying to keep iTunes. I have two M1 Macs in the house but they don’t run iTunes. I’m just looking for advice. Thanks.