Presents for "godparents"/shower host?

So here's the deal: My best friend just married my SO's best friend (we totz set them up and claim all the credit) and we want them to be our baby's godparents. I've known her and he's known him for 10 years, and I've known him and he's known her for 6 years. We trust and love them. She's going to be a doctor in a few months and he plans on being a stay-at-home dad (so we know our baby would be taken care of financially and emotionally), they're both socially liberal and non-religious like us, and they're both honest, good people who very much want kids of their own and love children. We told them we want them to be godparents, and they're both really excited. They hope to have their own kids after she finishes a year of medical residency, but they don't have any kids now.

She will also be hosting our baby shower. I really want to get them both a gift (or gifts?) but I have no idea what to get them! She is in all ways but blood a sister to me (I'm much closer to her than my sister) so I don't want to give something that's really generic or anything. Oh, and we were supposed to be in their wedding but missed it due to a kidney stone/hospitalization on my part (which some of you saw my post about). So I feel like this gift should be really good.

I Googled "gifts for godparents" but everything that came up was religious. That's the other thing--we're not doing this as a religious thing, even though I know that's what it comes from. I've actually been calling them our in-case-of-our-death-parents rather than "godparents." We plan on having a legal document drawn up that states they will get our son if something happens to us. There will be no Baptism or christening or any other religious ceremonies.

So how do you say, "Thanks for agreeing to love and raise and take care of my child in the event of my untimely death"? And, like I said, she's also throwing my shower, so also, "Thanks for spending your time and effort planning a party for me when I know you're busy finishing med school and beginning a marriage." Is there something traditional but non-religious you buy for godparents? I don't know anything about this kind of thing, so I don't want to not get something that's a must. Do we just get something really personal? Is a trip somewhere a good idea? For instance, they live in Orlando, so we could do something like give them tickets to Islands of Adventure (mainly because of Harry Potter Land). Some of her interests: science, medical stuff, tea (but NOT Tazo), wine, Harry Potter, ska music, adventures, movies that are not scary or depressing, ultimate frisbee, books that are either on something historical or scientific or sci-fi/fantasy with good characters, and her style is kind of hippie. Some of his interests: rock climbing, video games, computers, comics, beer (he likes good beer but can't drink a lot because he's epileptic), and surfing. I'm normally a creative person but I cannot think of anything good to get them and I want to make sure that whatever it is will really show them how much we appreciate them agreeing to be godparents. If it matters, we're all currently in Florida but she'll be starting a medical residency at the same time I start law school and we're trying really hard to go to the same school (or one in the same city) and will possibly be living together. The main places we're looking at: Portland, Oregon, New England, and Colorado--so there may not be much in the way of surfing or theme park trips after July of next year, but there will be cold. My shower will be in January or February, and the baby is due in March.

Thanks in advance for any suggestions! Sorry this is so long, I just thought more information would be better than less. Oh and one last question: is there a good name for godparents that doesn't have any religious connotations but is snappier than in-case-of-our-death-parents? I don't have anything against the religious connotation, I just don't want people thinking that means there's a christening, etc, and asking me why there isn't. I really see this as a legal thing more than anything--I love my SO's parents and I love my own parents, but if we die we think it would be best for Baby to go to our friends.

EDIT: I also kind of want to do something for my brother...if by chance we die and they die, or they can't handle the baby, I would want him to go to my brother. If we were doing "godparents" in the traditional sense, I would probably choose my brother as the "god father." He's the ONLY one of my siblings (out of 4 total) who has shown any interest in the baby. He never says anything to me without asking about the baby and without saying hello and goodbye to the baby; he desperately wants to spoil him; and he's already talking about all the things he wants to do with him. I want to show him how much I appreciate the amazing uncle I know he's going to be.