Lack of a stacking ring is only a problem if you want to keep them in cakeboxes and constantly dig through them. A stacking ring lets the writing surface hover above the next one.
Rima has lots of different varieties, this is just the first one that came up when I was searching at their site.
I’ve written on CD’s for years without issues. If you are worried, you could get the inkjet printable version instead. http://www.rima.com/prod/1161.html
Same high quality, different top surface.