I feel like you already have your answer, which is to install unraid, if you really just want to get it done.

But if you’re willing to take a little time to learn something new I’d go proxmox as it gives you tons of flexibility. You should be able to figure out quickly if unraid in a vm is going to work for you, and if not, abort and do bare metal.

If your concern is booting USB for unraid the solution is to sacrifice at least one of your drives as a boot drive, or if you have the room get a pair of small SAS drives and configure a raid 1 vol in the perc controller.