@roxie I had a similar situation on my rig and assuming modprobing the vfio stuff isn't good enough for your needs (I found it worked okay, yes the bios shows up on the wrong card and sits there awkwardly blinking once the kernel runs on the other, but once the VM runs it sorts itself out)
but yeah if that's not good enough for your needs my only option was to physically swap the cards, seemed the motherboard always init'ed the lowest card (for me anyway)