Can you get a PPL in a light sport. If so, will it only be good for light sport.

Tim

If the light sport aircraft is equipped with enough instruments, radios and lights to do the training required, then yes, you can do a PPL in a light sport aircraft. Remember there are night flight and instrument flight requirements for the PPL. The plane doesn't need to be instrument certified. You can also mix and match, doing some parts of the training (and testing) in one aircraft and the rest in a less expensive and less equipped aircraft.

Yes, and a private pilot certificate is a private pilot certificate.

Yup. Think of it this way: before the LSA classification was introduced, could you get your PPL in a plane that now happens to meet LSA requirements?