Just too expand a little on what Rules said. The reason he suggests 93/94 pistons is because they have a port in the skirt which has performance benefits.
You can replace just one piston if you have too, its not the best solution, however if money is a issue i would replace the one piston and put new rings on the other 3, if the base gaskets come out in one piece i re use them, same with the head gaskets. l spray them with copper permatex first
This is all fine and dandy, but do you know why it went bang in the first place? lf thats not dealt with it will just go bang again anyways.