I second Google voice.
Plus, with Google voice, you can continuously change your number if you feel the need to.
Personally, I find Google voice to be difficult to navigate but I have friends who swear by it. Remember, though, if you turn on Google voice to your phone, be sure to turn it back off when you're done!
What is nice about that service is all of your messages, and texts, are transcribed and save to your online inbox. That's a cool feature. Or a curse depending on how savvy you are about hiding things.
Good luck. Be safe. If you decide to purchase a cheap throw away phone, hide it well and only turn it on when you're about to meet someone or have to give a lady a call.