Go to all potential partners, although you might find the smaller ones easier to approach.

As someone mentioned, your sales pitch is basically selling the time to market & resources. If the feature is strategic, expect they will try to develop it themselves; if not, you are in with a shot.

For the first meeting, I would not spend too much time on NDA's & patents, however I would only talk about the overall solution and partnership. DNA's and patents will become important for the following meetings.

Go for it. The worst you could do is do nothing.

Good luck

PS: I think you will be pleasantly surprised on how much you will learn on your potential partners / competitors.