I have done a similar operation w/ CD-Rs . I simply used winrar like you said to segment the files, but instead mine were only 700 meg. There is an option inside winrar to create recovery info so you don’t lose the whole archive if some goes corrupt. This does make it a little bigger and take a little more time to make the rar files, but if you want to guarantee the archive I guess it is worth it. I don’t know Quickpar, but that might be the same or better, so maybe use both! In my case all the files were already in compressed form(.mp3 files) so I just selected “store” as the compression intesity to greatly cut down on archiving time.
BTW what exactly do you need to split up that won’t fit on a single DVD?! I guess you could be doint something similar to what I did, but I only segmented my music directory b/c I wanted to maintain directory structure of artist album etc… but if I had a DVD burner things prob woulda been diff since i used 16 cds which is roughly 2+ DVDs and I coulda just split the folder in half and drag’n’dropped. But whatever, I guess you got ur reasons
GL hope this helped