the important thing to remember here is that any technical person with experience is going to have an initial reaction of suspicion when approached by a business person with some wacky new idea. If you avoid everyone who initially reacts with suspicion, you will be limiting yourself to people who have not been approached by business people before.

That said, I agree that your co-founder and you have to agree the product is worthwhile. I'm just saying; don't expect this enthusiasm right off the bat; that is really only going to happen if your technical co-founder has never listened to a well-pitched bullshit idea.