The paraliminal tapes do not contain subliminal messages, don't worry. They help your mind and body to discover excelence in you. Meditation normaly striss your mind and it's good to use paraliminals to help you on the way.
There is also simmilar solutions as Hemi-Sync available with subliminal messages that you can record on your own. These are absolutely ok and please note that sometimes companies who are offering simmilar products can put some "colour" on what is good and what is bad for you. You have made a good decision to write for this forum, everyone is happy to give advice on your personal growth.