Hi Courior, the engine on the Super 8 is a KL25 KDU engine, the barrel and piston are GY6, as for exhausts...the barrel mountings can be very different ie. different angles, stud diameters and centres, at the other end mountings can be all over the place, so buy one which is specified as fitting Super 8, either 125 or 150. If you post on Super 8 150 you may get more ideas.
Hope this helps