I did have an SFXn for a short while. The camera performs well enough, but as you probably already know the autofocus is rather ponderous. However it can use any Pentax K fit lens, with the exception of some made for crop frame digital sensors and those without aperure rings (J type I think).

It was one of the first series of autofocus Pentax cameras, there was also an auto only version, which I think was the SF7, if I am wrong somebody will quickly correct me!