As far as the "other gear" part of your post, and turkey tips, that's a mouthful.
One thing, spring gobbler hunting is not the arcane, backwoods secret that it was when I was coming up, known only to tanned, wisend old men. There is a world of knowledge available in CD's, outdoor shows, and literature, and a beginner can learn more in one weekend studying same than they could in many seasons as years ago.
Do keep us advised on M500 barrels on 590's. I am a firm believer that a full choke, or more, is advisable for turkeys. And some sort of sight system to lay that load of shot in the head and neck!
Good luck with your spring hunt. It is my favorite and has provided many hours of fun (and frustration).