You could use any, though it would be more suitable to store onto DVD if you have a DVD burner as these can hold 4.7GB of data each, compared with about 730-800MB on a standard CD-R.
With it being a clean install with only a few programs on it, I would expect it only to take up 1-2 DVD's to make the whole image.
With CD-R's, you'd be expected to have about 8 for the same job
You'd then when running the program again (it'd boot up in dos), is Format (I think it has an option, though if not, you could use a boot up disc to do this) and then insert the DVD's one by one, letting it copy the data off each first and uncompressing them back to files
Your job would then be done, and it'd restart with your clean system fully loaded.