P320 compact with manual safety is the only catalog item. You'll need to put a carry grip module on it.

If you don't care about the manual safety (which if you're looking at commonality, you should) then a P320 Carry.

ETA : There should eventually be a commercial M18. I own 2 M17s and, while I plan on getting an M18 since we'll  also get them at work, in reality the only difference between the two are a .8" slide length difference. Both use the full-grip "Carry" module.

The M17 was sped for 17 rounds with a broad range of hand fit. Entrants had the ability to submit 2 guns to fill the needs for a compact and full-size (which SIG did) or to submit 1 gun that fit both requirements (like Glock did). The design of the P320 allows the M18 slide to basically be a spare part or accessory kit to the M17.

I think you'll see compact and subcompact grips in use over time, but the M18 as designed and issued is the M17 common grip module (the "carry" frame) with the M18 compact length slide.

As a complete aside, I think over time the M18 will become the prevalent issued configuration. The M17 was intended to replace the M9 and the M18 was intended to replace the M11 across the Army and eventually all services. However, the Navy, USMC, USAF, and USCG have all stated their intentions to adopt the M18 service-wide leaving the Army with the only service issuing a mix of M17s and M18.