I have the A4k version in my stock A4000, that I originally got when I traded it for an a1200, but its without software.
Unless I can find a full toaster/flyer/external HD case/accelerator with lotsa ram) for real cheap, I don't see using it. My Toshiba laptop/Pinnacle Studio/Canon FS200 setup works great, and is portable! Sorry.
Why not just use CF cards instead of hard drives? Even if you don't have a Flyer you can use your Video Toaster 4000 as a live switcher/effects/paintbox and input it into other editing systems.