Suppose they looked to the development academy leadership at top MLS clubs for such a role, are there any names that stand out to you as having a clue when it comes to advancing youth development nationwide?
I'd divide it into two buckets, coaching education people and organization/politics people. It's possible that one person could handle both but it'd be more realistic to put a duo in place who could each work to their strengths.
The USSF already has a director of coaching education, a Dutch guy named Nico Romeijn. He was hired in 2015 and previously performed a similar role for the KNVB. Many USSF technical staff including Romeijn keep a low profile, so it's hard to tell if (a) he's any good and (b) if he is good, whether he's been empowered to do his thing.
Whether Romeijn is the guy or someone else is needed, that's the sort of role in which I'd go with foreign expertise.
It makes more sense to have the organization/politics person be an American or at least someone who has a track record in US youth soccer. The reality is that US youth soccer is big and complicated. It takes a while to get a true sense of the lay of the land and there are a lot of prickly/arrogant coaches and clubs who need to be dealt with in a diplomatic fashion, however frustrating that may be.
I'd go with a development-minded GM or the right academy director. Dallas, RSL, Seattle, and NYRB are clubs that are doing some good things in terms of development/scouting/recruitment, so I'd look there first. I don't feel qualified to make specific recommendations because you really have to be up close to tease out the extent to which specific individuals are responsible for a club's success at youth development.
The realistic options really depend on the scope of the roles that the USSF carves out. If this GM position is really just going to hire/fire coaches and help monitor the player pool, that's a pretty limited role. I wouldn't leave an MLS GM job for that, for example.
Likewise, if the USSF wants to more specifically delineate the roles that we're talking about, how much power is delegated to them will determine the caliber of the interested pool.