That sounds like a complicated way of saying integrally suppressed rifle of a legal rifle length. That's not a SBR. I'd do an AR straightpull or Blaser R8 if your pockets are overflowing. That way you're not stuck with just the one suppressed barrel. Contenders and Encore would work as well.

https://youtu.be/Fh9OrVbU6G8?si=qRDpHLO-57bcV2Pb

https://youtu.be/ZxlaEaVFavs?si=YAFTmSJG1HyeUK2F