I like
Miriam. One of my co-workers has a daughter aged 12 named
Miriam.
Don't care for the other forms of
Miriam much. You didn't mention it but I can't resist mentioning how much I dislike
Maren! The ones you do mention are OK, but it seems like they would just mean a lifetime of explaining the spelling of your daughter's name. With
Miriam, most people would know how to spell it, I think.
I like
Miriam much better of
Mariah, which just makes me think of
Mariah Carey.