My 2017 is both a catcher and a pitcher, so we have gone through the various options for showcasing and camps.
I would say if your son has some good metrics to be captured, then be sure to do at least one PG Showcase. It does not really matter where, but sign-up as a dual player and PG will make sure your son gets to do both. The Pitcher Only players sit around a lot at these showcases and then they get to pitch multiple innings in one game. By signing up as a catcher, my son got his Pop time measured and his batting measures like Exit Velocity. Then when he checked into camp he always asked the PG guys if he could get an inning or two on the mound on Day 2. Each time he got a chance to pitch, and the PG guys would measure his pitching measures like FB velocity, curve and change-ups. And each of his scouting write-ups wrote him up for both catcher and pitcher.
I caution that if he does not have good metrics, at least yet, then do not do the PG showcase and instead focus on the showcase camps (like Headfirst if he has the grades or Showball). I saw a fair number of catchers at PG who had poor Pop measures, and scouts will note the pitching velocity too even if it is in the 70's. My 2017 waited until the end of Junior year to do his PG showcase when we knew he would score pretty highly. Ideally, play on a great travel team and that will get your son into the PG database and into tourneys where scouts will watch him play.
As a 2019, your son has plenty of time to get exposure. As another thread indicated, for many of us, our reflection is that the best thing you can do now for a Sophomore is get on the best travel team you can find for Summer ball going into Junior year and then Fall travel as well. If your 2019 is D1 talent, it will be obvious going through his HS season as a Sophomore on Varsity then playing on a strong travel team against top competition in the Summer and Fall. If he has not been "found" by Junior HS season, then it is pretty rare that he would get a chance to play D1. It took my 2017 awhile to accept that reality, but now he has a lot of options at the other levels and he is excited about finding the right match for academics, location and baseball.