Your biggest problem will be getting the timecode of the captured clips to match. So I recommend that you capture the entire tape in one go. Or a very few segments. Then you can do the same in HDV and possibly get the video cut to the exact beginning.
I would edit the material in an HDV project with the SD blown up. That way everything except the actual video is exactly the way you want it.
Just keep in mind that this is not a supported behavior. SO be careful and good luck to you.