A SG55/AG60 torch is a high frequency torch. If you try and hook up a IPT torch you will burn it up. Ask me how I know this. There are a few plasma cutters out there that use the Trafimet S45 and SL60 torch and fire it using high frequency, but it has to be timed just right or you melt the torch head. I have one here at the shop.
You are a lot better of with the Everlast.