Will the firs BLITZSAFE work with my CD for XM or DVD
pr should I buy the second one.
The difference in price is huge.
What makes them different?

http://www.logjamelectronics.com/blitzhonauxdmxv1.html ---- I want to buy it
or this one
http://www.logjamelectronics.com/log...alpdmxv1d.html

 

The first (cheap) one gives you a basic aux input into your stereo. The second (more expensive) one is a CD-changer controller + an additional aux input.

If I understand you correctly, you want the first (cheap) one.