Canned Oysters have been cooked by the canning process.
I don't think they'd be very good in a shooter.
You really want raw oysters along with the oyster liquor.
They might work in the Rockefeller if you were to cook the topping first and then put it on the canned oysters and then only heated it up.
Oysters are sorta like shrimp. You don't want to overcook them or you'll be chowing down on rubber.
Go with raw oysters if you can.
But I might be an oyster snob living on the Chesapeake Bay where I can get them off the boats.
On a side note:
In my youth I went oystering with a friend of mine who was a professional waterman.
It was January and after a day of "hard" work I've never been colder in my life.
I learned that day that this wasn't how I wanted to earn a living.
Since that day I've never complained about the price of oysters.