I agree with ultimateguitar and I'll add you should also beware of gibberish fonts:
http://www.hanzismatter.com/2009/11/another-set-of-gibberish-english.html. If you really want to get a Chinese tattoo, make sure you are 100% sure of the meaning (which means more than just looking the characters up in the dictionary). Ask someone you know who reads and writes Chinese about phrases that would be good for a tattoo.