If you're in the U.S., it'll be very difficult to even shoot an IPSC match. The vast majority here are USPSA, and Ghost connectors are legal, also in IDPA.
They are NOT legal in GSSF though.
There is an occasional IPSC match, but you can have all the fun you want by just omitting them and shooting USPSA and set the gun up the way you want. All my buddies run the Ghost Rocket and spring set. Great setup, ~3lb pull with overtravel stop.
Ron M. ('59 is my birth year)