I finally got my hand on the new Ruger 9mm carbine. It's the takedown version of the system that is extra nice for this camp carbine. It also takes Glock 9mm mags and has a threaded barrel compatible with the 9mm suppressor I already own.
Rumor has it an adjustable/folding stock will be available soon.
I will probably add a fixed 4x scope to finish it off.