Welcome to the site. The best thing you can do to get exposure to college scouts is to play on the best travel team you can find. The good travel programs have coaches who have contacts at colleges, and they take their teams to the tourneys where they know the scouts will be. Look for an organization that has a history of getting kids commitments. Tryouts for next years summer travel teams are coming up over the next month, so start researching tryout dates immediately. Once he's on a good travel team, narrow down his college choices to schools that fit his academic and athletic ability. Ultimately, he should choose a school he would want to attend even if he wasn't playing baseball.
You already have his measurables from PBR. Therefore, I wouldn't spend any more money on showcases or camps at this point. Instead, spend that money on strength/speed training and good hitting instruction. One of the common pieces of advice on this site regarding showcases is "don't showcase until you have something to show." The exception being if you have the extra money to spend and you want to document his steady progress each year. If PBR is good in your state, and he wants to go to college near home, don't waste your money on PG showcases.
There is more specific advice available on this site about certain types of schools such as high academic schools. I second the recommendation that you search old threads. I spent weeks researching old threads on here when I found the site. Feel free to ask questions, but you will learn more by researching the site first for general info, and then asking specific questions.