I'd definitely choose from the latter two. As I believe I've said, I've donated to Heifer in the past and I do like their model of teaching people how to farm/raise animals, and then pass on the increase to bootstrap other people in the local community. (If you dig deep down, Samaritan's Purse also has the option of donating food (animals or plants) to various communities, or at least they did. I sometimes do this, but more often donate for disaster relief.)
I know nothing about the Fox Institute, but as it may fulfill a human need (yes, as I said, I'm a cynic when it comes to disease-related orgs), it could be a valid choice. I do think that it's good to offer your customers a choice.
(As a long-standing supporter, I'm going to put a plug in here for Canine Companions for Independence, who raise and train service dogs. I see they currently get a 4* rating, which wasn't always the case. There are very few organizations that fulfill this need (Paws for a Cause is another), so that could be a potential option.)
