I use various stones for various things... but usually I use a quartz pyramid, it seems to be my favorite.

As far as the psalm goes, you could just find and print it out from online.. You do not have to be a particular religion to use the psalms for magick or spiritual work. The Hebrew mystics believed that there were certain phrases and energies within each psalm that contained mystical power. And when read, those powers are releases to help change whatever situation a person needs help with.

Many people who are not of the Jewish faith or Christian use the psalms in candle magick, crystal magick and other practices. Some even purchase a stand alone book that just contains the psalms for these purposes..... so fear not that you are partaking in a religious ritual.