I have an 870. Looking to add a little to it. I have a tactical light and I have a 6 shell saddle on the side and that's about it. I would like to add the 8 shell saddle with short rail from Mesa Tactical. But I think you need a shorter forend and can't find one. I would also like to add some sort of pistol grip butt stock also. One that holds more shells though preferably. But telescoping is okay I guess, if its good. I just want to hold as many shells as possible. Also wanting to get the door breeching barrel, think its 18 1/2 inch.. Any help with setup ideas?? And with an 8.5 inch barrel, what kind of mag extension can I have. I have one now I think its 2.