cebu75, I don't mean to disparage, but based on your post it doesn't sound like you have a good idea where your son currently fits as a college prospect, yet. More free advice (worth every penny):
First, you really need to know his best position (from a recruiting standpoint). If his best position is COF and coaches are only seeing him at SS, then he's hurting his chances. If his travel team hasn't helped you figure that out, a college camp this fall might be a big help. You mentioned HA, and given your location, I would recommend a Patriot League school. He can ask them their opinion about where he is best suited. Coaches tend to see you in specific spots based on your skillset.
Once you figure out his best position, you need to get an idea of his level of play. If a Patriot League team loves him, then you know he has D1 options. (Patriot League teams are generally on the less competitive end of D1.) If zero interest from Patriot as a junior, then he's probably looking at D2/D3.
Once you have an idea about his level of play, you can start targeting schools. Make a list of at least 10 schools where you can realistically see him starting as a freshman. Add all the characteristics of the schools that are important to him (e.g. location, cost, majors, probability of acceptance, competitiveness of baseball program, etc.)
Once you have a list to work with, then you work on getting in front of those schools. College camps can be ok for that as long as you are a legit recruit for that school. Camps work better if the school knows you before you show up. That way they're paying attention to you the whole time, not just waiting for you to catch their eyes. Lots of recruiting happens at Diamond Nation, but mostly from coaches showing up to evaluate specific players. Give a coach a reason to come see you at DN (like really good numbers at a PBR showcase) and they will come.
Regarding some of your other questions... Most PBR showcases are less than $200. That's a good place to get his measurables documented. Check NJ, PA and NY for one that works for you. D2/D3 schools love interest from underclassmen, but most of the action for them is after the junior year high school season. Most college coaches (especially D2/D3) still love guys who hit hard line drives. By all means, he should keep getting stronger and hitting the ball harder (exit velo), but the K/HR equation in college is still completely different than MLB.
Best of luck to your son, and please continue to update us on his progress.