There's a reason pistol grip shotguns are called "cruisers" they really are only good for if you have to get out of a car with a shotgun and immediately engage targets. They really are a one trick pony.
Shotguns with slugs are easily capable of hitting COM with slugs at 100 yards, so with a PG only, you'd be killing your effective range.
Best option should be a folding or collapsing stock. You get the short OAL, bue still have the stock for long range accuracy, OR more importantly, close range fast follow up shots.