Dirk,
I applaud the effort to ask questions, research the topic, and have a starting point. IMHO, you've selected some top national athletic showcases to hopefully appeal to ACC/SEC schools and blended in Stanford and Harvard for presumably academic showcases.
I have three comments. First, these choices are on opposite sides of the country and opposite sides of the athletic & academic recruiting spectrum although I would consider Stanford to be both. You may want to try a local/regional showcase first before spending a large chunk of change as a HS sophomore. If you go to a more regional showcase first, I think your son will get a sense for the appropriate level of showcase baseball and your investment dollars.
The national showcase experience is incredible but there are literally many-many hundreds of talented kids who don't get noticed at these events. You'll want to find an event where your son stands out. Second, I know many folks that have gone to the Harvard camp over the years. I don't think the number of schools represented even came close to 100. You may want to double-check on that.
Lastly, Keewart brought up HeadFirst, and I think that is the still largest and broadest academic showcase around. You'll have most of the Ivys, Patriot and academic D3s. That may be a better approach than just attending the Harvard camp. There are a handful of other academic showcases.
FWIW - My son went to PG WWBA & Fort Myers many, many times with his national travel team...won PG WWBA it in 2008. He is a RHP who topped out in the low 90s, but cruised in the mid to upper 80s in high school. He knows how to pitch. He had excellent grades (and SATS) like your son. By no means did my son stand out at these national PG events. We ended up changing our focus & strategy late junior year from top athletic PG events to more academic events, and the results were extremely positive. So, my advice is go to these events if you have the resources, but be flexible with your focus & strategy of trying to appeal to both the top athletic and top academic. Listen to the feedback.
Good luck!