Whoops, is this SD material? I totally failed to read that between the lines.
Yeah, SD to HD with an interlaced-to-progressive conversion and a time-base change
and going from 60i to 24p? That's the nightmare scenario.
If it were all the same raster ? and this is what I came back here to say, 'cause I didn't think to before ? the "correct" thing to do in this case is to insert pulldown into the 24p material and just cut it with the 60i stuff
if you have the option of delivering a 60i master. Like if you're delivering for television, or for DVD authoring and duplication.
If you don't have the option of delivering 60i, then do what Shane said, except do a very small test first. Because the render times will be outrageous, and you still might not get results that meet your approval.