It's really Want vs Need.
For a dedicated turkey gun, all you'll NEED is a single shot 12ga.
-H&R or NEF single shot. Beware-these kick like mules with a turkey load in them!
For versatility you'll WANT a shotgun with follow-up shots. A pump will get you there.
-Rem 870, Win. SXP, Benelli Nova, Browning BPS
For more versatility, and faster follow-up shots you'll WANT a semi-auto.
-Benelli M2 & SBE II, Remingtons 1100, 11-87 and Versa Max, Browning Gold & Maxus, Stoeger 2000
Have fun! Whatever you get, pattern the gun and practice.