This would be my line-up.
I chose Elsa Bloodstone as a member because I like her, she could be fun, and she has been a lot more popular than some of the characters that have been part of the Midnight Sons, having been in Bloodstone, Nextwave, Legion of Monsters and Marvel Zombies, plus appearing in Avengers Alliance and Marvel Future Fight.
Of course there's nothing that limits the team to one female character, but I think most female supernatural characters aren't really very interesting. I'm pretty sure nobody really cares about Victoria Montesi anymore. I really don't care about Jennifer Kale. Looking at other potential members we have Topaz, who nobody really cares about. Scarlet Witch and Nico Minoru are more popular, but I feel they'd work better in other movies. Also, both don't seem very knowledgable in supernatural stuff, or at least wouldn't be early on in the MCU.
Clea is one character that I could see working as well, but I don't know a lot about her. And then there's Satana, who
could work as well, but I'm afraid she'd just turn completely evil at some point because the writers don't know what to do with her (the same holds for Daimon, btw).