I have used various Mossbergs over the years and absolutely love them. Some people call them cheap and ugly....but they sure hold a pattern and keep knocking them dead. Don't buy into the belief that you need a 3.5 inch shell to kill a bird. All my birds have been killed with HV 3 inch loads. Heck, I took my wife's 20 gauge out this fall just to prove it could do the job. With a XXX full choke it rivals the patterns of some of my best 12 gauge patterns! Several of my hardcore turkey buddies actually use 3 in loads out of their 3.5 in guns....due to better patterning.
I would urge you to look into some tight, high quality chokes and after market adjustable sights or optics. I have a Tasco red dot on my turkey slayer and absolutely love it. With my .665 XXX full Hastings choke, it is deadly out to 40+ yards.
In reality, any gun manufacturer out there can make a decent turkey gun. Getting the gun....and then getting to know the gun, load and choke is what is important.