The correct Wilson Combat Gas Tube for your Wilson Combat Match Grade Barrel is the rifle length model: MPN:TR-GTR.
The correct size Wilson Combat Gas Tube for your 18" Wilson Combat 5.56 barrel is the rifle length model (MPN:TR-GTR).
The Wilson Combat AR-15 5.56 NATO 16" Paul Howe Match Grade Barrel uses an intermediate length gas system and would require an intermediate length gas tube (MPN:TR-GTI).
That will be between a pistol length and a rifle length gas tube. you'll have to measure the length to find out. but most likely a rifle length.
At 20 inches you could still use a mid length gas tube, past 20 inches you would use the rifle length gas tube.
You will need a carbine length gas tube.
You will need either a carbine length gas tube.
You will need the carbine length gas tube.
That barrel would be considered rifle length, as per Wilson Combat.
Yes this will work with your gas block as long as you buy the right size gas tube.