I always regarded Ground Zero Games' NSL line as good Imperial Guard proxies, looking a little bit like Mordian Iron soldiers. The only thing missing so far was proper character models and vehicles. So I ordered some Winter Command figures from Vanguard Miniatures' Novan Regulars and a few GZG head-swaps later I was ready to go. The Ogryns are "Space Ogres" from CP models by the way.
Being proxies they are not perfect, for sure. But they look "guard" enough to me and I can field Chimeras, Ogryns, Kasrkin, Guardsmen, Weapon teams and powerfist-wielding Sergeants and Commissars. Last additions will be Leman Russ and Sentinels.