Don't waste your money, I bought a 870 that came with a pattern master choke missed more ducks with it then I can count switched back to a factory modified and the dead ducks tell the story.
you have a bigger problem than which choke to use. If you booked with Froggy it will not much matter, you will not shoot very much if at all.
I went with another guide a few years ago and did not shoot but once and killed one bird. Me and my son will have fun whether we shoot or not. I am willing to try Froggy, he is booked solid with many repeats so he must have something going on. In my experience when it comes to hunting whether alone or with a guide, it is never a guarantee. If it was a guarantee then it would be called killing. Every one knows that if you want to pile them up like on TV you gotta pay a lot more money and travel much farther.