Any machine capable of throwing a target 70 yards can be used, event the old winchester single stacks had an international arm. We have two with the international arms and the trays / rails are still sold by QRP. The main expense is the ISU delay timer. If you want to go fancy and get one with the lights etc, the price is a little daunting. Most manufactureres will sell you a machine with the timer built in. A cheaper option would be to buy a timer from clay delay (google it). They used to make a basic in line delay timer for about $100. Or you can go up to a fancier unit with wireless voice release for about $300. Like I said, for international I have seen almost any machine used, including Winchester. Likely Laporte is the most widely used, but all the major brands will work (Promatic / Beomat / GMV / Bowman / Serena / Due-matic etc etc). We use winchester and Bowman skeet machines and have no issues getting the distance.
