There, fixed that for 'ya.
Honestly, unless your encoding consists solely of one-minute-or-less, 160x120 clips encoded into Cinepak; you do *NOT* want to use a 68k machine. Even a Q840AV chipped to 66 MHz would be nearly unusable to produce modern style video.
Yes, I know those machines were primary video machines back in the day; but modern codecs are just so much better. Those modern codecs DEMAND a newer/faster machine.
If you are going to be using it for video encoding, I would suggest an Intel Mini. If you can find a Core 2 Duo cheaply, great; if not, even the 1.5 GHz Core Solo is faster at encoding video than a dual-CPU 1 GHz G4. (Yes, I know that comparison from personal experience.)
If you want it specifically to experience video editing as it was back then; not as a useful video editor, then by all means, go ahead. But don't expect to get anything 'serious' done on it.
(For example, running HandBrake on my 466 MHz G4, encoding a DVD into 'iPod High Res' format takes somewhere around a week.)