My word of advice would be to check with your friend first and make sure he wants a new puppy right now. For example, when my father-in-law had to have his elderly, well-loved black lab put to sleep, my husband and I considered getting him a new puppy once a little time had passed. However, we brought the matter of getting a new dog up with my father-in-law in the course of regular conversation, and we found out that they did not want another dog. (My in-laws are retired and travel a lot.) We never told him that we were considering getting him a dog, but we still were able to find out his wishes.

As for the type of dog, I think the personalites of the parents would have a lot to do with how good of a mix that would be.