I am archiving clips in MPEG to create a library (20-30 minutes each) onto CDs. The choice is MPEG 1 or 2. Here are the considerations:

I will have to compine/edit/sequence these later, so decoding compatibility is important - Virtualdub is very good, but only does MPEG1, as do others.

The MPEG to AVI process seems perfect - just frame captures, am I right?

MPEG2 has higher compression, so it looses more data than MPEG1, right? However, SVCD and DVD use 4x (2x vert and 2x horiz for DVD) more resolution than VCD, so it generally looks better even though a little more was thrown away, right?

How does 720x480 MPEG1 vs 720x480 MPEG2 (both CBR) compare (microscopically ?

And after converting to AVI, combining, sequencing, and recoding into VCD or SVCD, there will no doubt be some blocky delta frames. Would choosing MPEG1 or 2 originally (in the clip format) keep this down, or when recoding in a final creation, would MPEG 1 or 2 offer any less degradation as a final format (VCD vs SVCD vs XVCD)?

Do the 2 formats use different 'block' sizes such that it would be best to recode the same way so that the 'blocks' (that show up after decoding the original MPEG clip) would line up? I know that's not the technical description, but I hope it carries the question through

I've done a couple passes and things seem to hold up well either way, but I'm looking to invest weeks in archiving and would like to do it right the first time... There are more tools available that read and work MPEG1, so I'm hoping that at comparable resolutions it won't matter and MPEG1 will work, but what is the expert opinion?

Thanks.