There are several 9mm carbines and braced pistols on the market to choose from, but few choices for .45 ACP. Off the top of my head, there's just AR-pattern, the MPA MAC clones, the Kahr Thompson, and the Kriss.

From a practicality standpoint, only the AR pattern option makes any kind of sense, but is there anything else out there? Any readily-available HK copies, etc?