Memorial tree

A coworker had twins a month ago. Unfortunately, after a month long battle the baby succombed to a birth defect and passed on. My office would like to purchase a flowering tree or bush for the family in rememberance. I volunteered to do the research as to what kind of plant. I’ve tentatively narrowed it down to the autumn cherry tree or the kwanzan cherry tree.

Id like the tree to be hardy to zone 5 and thrive in partial to full sun. Low maintenance and not susceptible to many diseases
would be ideal as well. Do any of you have any experience with these trees or could recommend any others? Thanks.