Get an M2...26". I just did about 2 months ago and have 500 rounds through it. Awesome. I went with the M2 over the SBE II for reasons which seem like they would apply to you as well.
I want it primarily for pheasants and trap shooting. With lighter trap/clays loads, the M2 is less likely to have cycling issues than the 3-1/2 inch capable SBE II.
I do hunt turkeys as well, but I've got my Browning pump all set up for that......still like having the M2 as a turkey option, though, and 3" loads are more than enough in my opinion, if your aim is on the money.
With your situation, I'd just be a bit concerned that the SBE II might not cycle 1 oz. trap/clays loads each and every time, but the M2 will....
Jeff.