That's how I'm doing my Inquisitorial stormtroopers in my Inquisitor warband. I just use some Sergeant Dorian Black and Major Jackson models, some spare 40K bits, green stuff for the armour plates and voila. Instant Inquisitorial stormtroopers. Aim to have at least three Inq. Stromtroopers in my warband before they're discontinued. I can't even get any more Inquisitor Eisenhorn or adeptus arbites models (excluding Special Security Enforcer Barbaretta) anymore.