I love Kelila Michal... my Hebrew name is Kelilah. :-) that's a gorgeous combo. I would probably use it as a fn, although here are some of my mn combos:
Sadie Michal (after great-grandmother)
Anne Michal (great-aunt)
Leah Michal (Biblical)
Eva Michal (Biblical)
Noa Michal (Biblical)
Nava Michal (I just like it)
Danya Michal (variant on a Biblical name)
what do you think?