First but the video on DVD with something like a http://www.amazon.com/Sony-VRDMC6-DVDirect-Compact-Recording/dp/B002EVP85K/
Now you can rip the DVD over USB.
And no, there has never been a firewire to usb convertor.
I have had to change computers due to failures and my new one only has USB ports. How can I download my videos from my Sony DCR-TRV330 using a USB port?