This motherboard is really one of a kind as it's probably the only ASUS one without FW. In addition you only have PCI Express slots running from x4 to x16…verylikely intended for video apps.
You can add a FireWire PCI Express card in the lowest socket (white one). This will add FW ports to your PC.
Adpters shouldn't even be considered for these apps.
The limitation you may have is that multiple FW drivers may not be used by your software. I'm not experienced in Cakewalk Sonar.
If you use a FW audio interface and the H8000FW on FW, their 2 drivers may not run together. ProTools and Logic can "aggregate" FW drivers and work fine.
You won't need the plugin to get audio in/out. It only takes FW or any audio interface I/Os.