I’m looking to work with a KDE distro on my RP4. I’m most familiar with the Ubuntu family but it doesn’t seem Kubuntu has an ARM image.
Fedora has a KDE spin but not sure I want to go that route just yet. Any suggestions?
Yes, start with the lite version of RpiOS and install KDE on it. You could actually do the same with the full version (which might make it easier in some ways).
On normative linux installs (such as RpiOS or Ubuntu), you do not need to switch distros to switch DE's. The reason for the various "spins" is to make it easier1 and provide some customizations by the distro (so you don't just get KDE decor, you get eg. Fedora decor too).
In fact, DE's are really specific to the user, not to the distro or the individual system, meaning it is easily possible (given enough RAM) to run multiple DE's simultaneously -- although if you only have one screen/keyboard interface you obviously have to switch back and forth, this is easy enough as well. In other words, you could start with the full version of RpiOS and be able to run either KDE or the default LXDE derivitive.
There are two basic steps to this:
apt install kde-full.