I think Brina Grace sounds very pretty and very versatile. I tend to think of names through life stages. How does it sound for a baby? for an elementary school kid? for a high school cheerleader/athlete/valedictorian/etc? up to CEO of a large major corporation?
Some names don't sound right for all of those life stages or life choices and I like names that work for all of them. I think Brina Grace works for all of them.
I personally like Cassie as a first name for a girl. I like Elizabeth as a middle name, but that feels so over-used as a middle name these days.
I'm in a similar predicament as you, Hollyberries, for a boy name. My dh is a third and has said that he doesn't want there to be a fourth, though he feels like he would be pressured to continue the name. I suspect that has something to do with why he wants to have a girl.
Now if I could only get pregnant...