You can do the same with a Ruger Super Warhawk! Expand the Cylinder to 8 Rounds add the Ammo skip system, Smartlink, extended Barrel .Thats even better than the shotgun because you only need a free Action to choose your Bullet 
with an even better Dance
Medicineman
Oh, for true. The Ruger Super Warhawk is a beautiful thing. A whole step up in damage to 6P with -2AP, and you can do wacky loads for maximum utility. Potentially you can mod it for SA fire or double up with one in each hand. It's the biggest damn pistol there is, but it can't mount a silencer (and the revolver silencer mod? 2500¥ 16F? yikes.)
Strangely enough, you can put a silencer on a shotgun, but not on a magnum revolver. Though there are plenty of other good pistol choices that fit with a stealth-kill option, but they've all got clips, so trying to keep a Mac Guyver load-out is difficult.
Hell, you could just keep a brace of holdout pistols loaded with various things and work it that way. That would be pretty cool.
Edit: Oh! almost forgot! Choke rules.
When shooting Flechette or shot, you can change the spread on a shotgun as a simple or free action (depending on whether or not it is a smartlinked weapon.) Quick breakdown of flechette: its code is +2 damage +5 armor, so it does more damage, but gives the target 5 more dice on his armor for resistance. The net gain here is small, however it does use impact armor instead of ballistic armor, so there can be benefit there, since most guys don't have much impact resistance.
Now, Narrow choke does regular damage (in the case of flechette in the sawed off, that would be 7P(+hits) +4AP or 5P(+hits) -1AP for slug/00.) Nothing special here. All standard.
Medium choke
decreases the damage done by 2 and
increases the AP by 2, but also reduces the defender's dodge pool by 2 and can hit two targets within one meter of each other. It kind of sucks, but it does make it more likely to hit and lets you tag a couple guys in one shot without a penalty for shooting at multiple targets in a pass. So 5P(+hits) +6AP Fletchette or 3P(+hits) +1AP 00 Buck, both with a reduced dodge pool of 2 and the potential to hit a couple guys. Two shots should be pretty much guaranteed to knock them both into stun overflow.
Wide choke decreases the damage done by 4 and increases the AP by 4, reducing the dodge pool by 4 and allowing 3 targets to be hit at once. Here is where the fact that you've got a pistol-shotgun is going to suck. Normally you'd be using a 7P base weapon with these choke rules... Anyway, what you've got here is 3P(+hits) +8AP Fletchette or 1P(+hits) +3AP 00 Buck, both with a reduced dodge pool of 4 and the potential to hit three guys simultaneously.
Obviously, the last one there is only really useful for doing minor stun damage to crowds, since the modified Armor value will be so much higher than what kind of damage you're putting out. Might be good enough to force a crash test if you're trying to shoot bikers off your ass, but I'd stay away from it. Really, the only time you'd want to use Wide choke is with an Auto-fire capable shotgun that you're using to try to simulate a more economic version of Suppressive Fire. A wide-choke long-burst with an Auto-Assault 16 is, after autofire DV bonuses, 11P(+hits) +8AP with -4 to dodge, all aimed at 3 potential targets. That's much more reasonable, and more likely to hit, than trying to engage 3 targets with a Full burst from an assault rifle for -2 dice per additional target... even if the AR is going to be doing physical damage to the AA-16's stun...
The choke rules are laid out in the core book on pages 154-155.
