I’ve been using infomaniak for a while which suits my needs pretty well. It’s mostly intended for businesses but it’s very usable as an individual. Lots of storage for a decent price too and has all the functions you mentioned. Hosted in Switzerland.
Most cars I’ve been in newer than 2015 or so can automatically switch their radios between FM and DAB, some smoother than others. So the technology must exist, but I don’t know if its available in freestanding radio units.