Trust me, Black Majok, you want another 870. A box stock 870 with a short barrel is an outstanding combat shotgun.
Let's do the math....
Out the door, that Benelli will run you close to $900.
New 870 HD-$300.
Weekend at Shootin' Skuhl, $300.
A flat of STS bird loads for practice, lots of buck and slugs-$200 or whatever you want.
So for the price of the Benelli, a decent shotgun, you can not only pick up one of the finest fighting tools yet devised, but ammo and some expertise.
The bellsnwhistles can be added later, if you still want them.