Unless you need to comply with western rules, I'll say the 28" stainless. Stock type is up to you.
I own a few muzzy rifles, some with 28" barrels and some with 26". All are in-lines. One of these is an Accura stainless/camo standard stock and I love the gun. We all know we need to wear hearing protection when shooting but I am going to say that from the hearing comfort standpoint guns with the longer barrels are easier on the ears even with good muffs being worn. That couple extra inches does a lot to put the blast further in front of you. The longer barrels also help lessen barrel jump or climb when the gun is fired. I just know that shooting one of my 26" barreled guns weighing roughly the same as my 28" guns is somewhat less comfortable using an identical charge and bullet.
I don't think you'll gain much in the fps department with a 30" barrel other than weight. I can't address long range [300 yards plus] accuracy with a 30" barrel for lack of first hand experience. Some may argue that a 26 inch gun goes thru the woods easier but I have never found any problems with the 28's that I use.
How the gun fits you can come into play too so be sure to shoulder a bunch of different brands before starting to settle on one.
I'm one of those "inside 100 yard" hunters but I also enjoy punching paper at 100 yards. I don't go beyond that because I'm general too damned lazy to walk down any further to pin up a target. I have no doubt that a 28" Accura can be shot out to 300 yards with a proper load and bullet. I have no doubt that a 26" or 27" or 30" can do the same, but I like my 28" for the reasons I mentioned.