45acp is NOT difficult to suppress !
Its a matter of what type of pistol, replacing the barrel with a threaded barrel and setting it up to run.
OR Buy ak HK USP Tactical. but a supressor and screw it on !
Someone was just giving you bad info.
Glocks and HK are simple, 1911's a little tricker due to barrel lock up system
and having slide recipricate properly.
FYI