Are you planning on burning them back to CD-R's or are you going to mount them right from the DVD-R?
What software are you using to image/backup the games? Are the games copy protected?
If they are, you may want to an image format that's more native to Blindwrite, CloneCD, or Alcohol 120% and then throw a setup of the version you used onto the DVD-R also. The native formats of these three programs save alot of extra information that may be needed for a backup to work correctly.
If they are not copy protected, then I'd just stick with the ISO format. The CUE/BIN format has been dying very slowly for a long time. Its just a matter of time, in my opinion. Plus, not every cd burning software supports it (still).