I really wished I had done with my grandfather what you and your sister did with yours!
Your friend can email us at contact@heyartifact.com. George, my co-founder, will follow up from there.
Regarding biographies - great question. We don't currently do this, but it's an idea that make a lot of sense as extension of "Life Story" Artifacts. And in a lot of respects, "Life Story" Artifacts, which occur over 3 to 4 interviews, end up feeling a lot like an "audio biography" - with that intimacy of having the person's voice right there.
Thank for the suggestion and please do have your friend email us!