Can someone tell me which 16" upper would be best to use for a AAC 762-SDN-6 suppressor?  The choices are 16" barrel w/carbine gas system or 16" barrel w/middy gas system?  I vaguely recall reading somewhere online that a middy may not reliably function with a suppressor without juggling the buffer weight to tune it to the ammo being used.  Right now my 11.5" Noveske will eat anything I throw at it without fuss.  I would like the same performance out of a non-NFA upper.  Would dropping the barrel length to 14.5" hinder or help?

Thanks