Buy cheap buy twice. I would stick with the bodyguard over any kel-tec. Is your budget really so tight that you have spare funds for a kel-tec and not a lc9? I would be happy with what you have until you can save up for a M&P shield or compact, Glock, Kahr, XD or Ruger.
The practice ammo and enough carry ammo to verify function is going to cost more than any of these guns. When you look at the total cost for employing a new gun, holster, ammo, range time of well over $1000 the difference in price of a Kel-Tec and M&P shield does not seems so much after all. You should stick with what you have and wait untill you can do it right.