you should be able to write your own mantra or whatever. I wouldn't really pay for anything. It makes it more personal and close to my heart then. Personally I think my meditation style is relaxing in prayer...
There is actually a TTC meditation CD you can download off the net. You have to pay (i think), but Im planning on downloading it for my next IVF.
The website is anjionline dot com.
They say it can help, and well it sure can't hurt right? at the least it will help with the whole stress that ttc brings! i've started yoga recently, trying to do any and everything we can to help all of this!