Most modern computers come with one, standard. If yours does not, you can get a FireWire card to pop onto the computer's motherboard.
I don't know about cheap dv recorders/decks, but most mini-DV camcorders should do. If you're just using it to import/export video, there are plenty of cheap models. Family-picnic style. Just make sure it has a FireWire plug on it. (A few models don't)
Then you just need a cable to connect it to the computer.