hi!
there is one really nice feature of sony d-8 camcorders. they have analog in. with a small hack (available on the web) you can enable av-in > dv-out. it means that you capture from vhs or s-vhs source to the hard disk, in dv codec, and use that capture together with dv capture. so the camera is acting as a analog>digital converter, and you should know that proffesional machines for that conversion are about $3000 up.
probably this is your answer.
to do the hack you will need lanc>paralel cable and a small piece of software. the software is usually been used to enable dv-in on european type of cameras that have dv-in disabled by default.
yes, dv and d8 are same format. only diff is media - d8 is using same old hi'8 tapes, but the video recorded on the tape is binary, the same format as dv.
dv cameras sometimes are using better technology (3ccd, good lenses) so it makes them better than d8. for home use this is not relevant because the price diff (3ccd dv vs d8)is very big.
regards