A talented director is already interested
Neil Marshall, who you probably know best for directing Game of Thrones (the epic battle-infused "Blackwater" from Season 2 and "The Watchers on the Wall" from Season 4), was asked if he'd like to make a female led comic movie, and he was clear about his interest:
"I would love to do a Black Widow movie. That’s perfect, I would love to do that. That character is really interesting, she doesn’t have any superpowers, she just has extraordinary skills, and the world that she comes from, being this ex-K.G.B. assassin, I find that really fascinating, yeah."
If you've seen "The Watchers on the Wall," you know he's got the chops. Heck, he was just nominated for an Emmy for his work on that episode. And Game of Thrones, from a directorial standpoint, isn't just the best you'll see on television -- it's better made than a lot of high-end movies we've seen.
The point is, where there's one good director openly interested, you can expect there are others, too. So from directorial standpoint, Black Widow is easily covered.