RE: New gun time.
I have not seen the 3.5" 1187s for much under $900... and it is $900 poorly spent in my experience. The supermags I have had contact with have not functioned well with any shells at all, of any length. The 3" models do much better. The SPR 453 is a hit or miss operation. I have seen some that will go like hell with whatever you feed them and some that were so poorly made that they wouldn't even assemble. Half (and I mean litterally, not figuratively half) of the ones our shop sold came back, went back and never came back.
Jack you don't need a 3.5 shell for anything. You don't get any more range out of one either. All you get is more pellets and less money. And of course more noise and recoil. Most of the guys in my club who shoot 3.5" shells can't shoot very well, and they think the reason is because 2 3/4 or 3" shells cannot kill ducks at decoy or close passing distances. The reality is they just can't shoot. A big part of that may be linked to the fact that they are getting slammed with recoil everytime they pull the trigger and have developed a flinch that is making them stop their swing. Just some food for thought.
One other bit of advice.... when it comes to semi-automatic duck hunting shotguns.... you get what you pay for.... don't expect a Lexus when you pay for a Kia.