Were i can buy the original pressing of cd, i've got only remastered cd
Most likely eBay and depending on the CD you'll be paying a fortune.
Read this http://www.keithhirsch.com/target-cds
I search for these CDs from ebay and they tend to be expensive.
There are also later pressings that are good.
Another source for info is Steve Hoffman's http://www.stevehoffman.tv/forums