Looks like only CO2 replicas can be used for IPAS, although a google search of "IPAS" yields some amusing results .
Having used a couple of replicas in the past I'm not a fan. Just too low power output and cheap feeling, although the quality appears to have improved on some of the newer models. I guess my favourite handgun is plastic anyway, Glock 19.
I get to go "real" pistol shooting just about every month, so that box is ticked.
It's a bloody minefield this shooting lark.