Seems to have decent parts, it all depends on who did the motor, if it wasn't done by a reputable engine builder id shy away from any re-build or you might be doing most of that list again.
Popping can be any number of things, but 9 times outta 10 if he did that much work to the car he will be on this board someplace, if your seriously interested in that car ask him what his screen name is, people cant hide too much on this site....Good luck.