I have one, and Armbian has an official release for it and works quite well with a Kioxia 512GB NVMe.
But at this moment I’m just saying there are similar boards out there, and the 5 Plus might be slightly cheaper (no wireless though). Radxa also has a similar board based on same SoC but only has one GbE port and price might be similar to the Banana Pi.
The competitor is the Orange Pi 5 Plus, also has 2x 2.5GB Ethernet, same SoC, more USBports, no integrated WiFi+BT (optional M.2 module), eMMC connector, M.2 NVMe socket (up to 2280).
There are several solutions but will be above the budget. Best solution is the Argon Eon case for the RPi 4. I’m waiting for a version for the RPi 5.
Can house the Pi and either 4x 2.5" drives or 2x 2.5" and 2x 3.5" drives, all SATA.
Windows guests also run fine on KVM, use the Virtio drivers from Fedora project.