My advice after having just gone through this, would be to find a shop that has a large selection of 18" barreled HD shotguns so you can fondle them all.

I found the Mossbergs to feel flimsy and cheaply put together (poor fit quality). They were lighter than the Remington 870 Tactical (ghost ring sights), but the 870 felt amazing to me. Very tight, smooth and pointed naturally for me whenever I shouldered it. I love the location of the safety and the action release on the 870, so thats what I went with.

If you get a pistol grip preinstalled, see if you can try one out. The shop I went to had a pistol grip Mossberg that I was unable to operate the action release. Even while looking down, I simply could not wrap my fingers around and operate it, because the pistol grip got in the way.

Plus for the Rem870 Tactical (81198) is that it comes with the picatinny rail for your Eotech, built in ghost ring sights (XS brand) and it has a plethora of parts online for it. As enticing as the Rem870 Synthetic 7rd is for $350, avoid it. It doesn't have a removable choke, whereas the Rem870 Tactical (81198) DOES have a removable choke (comes with the ugly "door breacher" thing). Also, the receiver isn't drilled for sights/rail, whereas the Tactical version comes factory drilled with rail/ghost rings installed.