Either of the shotguns you mentioned will be perfectly fine for turkey hunting, once you decide which one you want to go with let me know, and I will be happy to let you know what choke/load combos I have had success with.
I agree with southern, you do not need decoys....sometimes it is nice to have them, but you do not need them.
You don't really need a ground blind, but lots of people use them and they do work fine so that is really up to you.
Good luck, if you have questions just fire away!