Vance is unattractive to me. It sort of reminds me of a cheap romance novel stud, or a fifties throwback troublemaker like in a lot of
Stephen King books.
I like
Courtney on a girl. It might have been trendy back in the early seventies, but it definitely lost that trendiness long before now. I think it's gross on a boy, like the name a sitcom writer would give the stereotypical obnoxious nerdy boy. I would honor your male friend
Courtney by using his middle name, if he has one, or letting him pick the name, if honoring him is that important. Much nicer on a girl.