FireWire is about dead on mainstream laptops. You are looking at the custom stuff if you want that.
I have a FireWire interface that has been going strong for 10+ years, and I had to add a PCIe 1394 card to my latest desktop build to keep it working.
If I needed to add audio to my laptop now, I would probably spend the money on a good USB interface. FireWire seems to have reached end of life as a technology.