A few things
1. There is no recruiting until you're a college prospect. I'm not saying your son is not good at baseball, what I am saying is he does not have a single metric or attribute that would make him appealing to a college coach right now. There is not a single reason to ramp up recruiting efforts at this point. What he should be doing is playing up in age at 17u to play better competition.
2. He has to get bigger. I understand this takes time but now diet and weight training are not optional when trying to become a college level player, they're necessary. 6' 145 is small, he's young it's fine, but the goal for next baseball season should be at least 165lbs.
3. Don't attend another showcase that is not already included with his travel program until he either throws 85mph from the mound or is a high level high school level bat weighing 165 lbs. PG and PBR can be useful tools for some guys. Not for your son, not yet. If your son is a future D1 player he's too small and too slow right now. If your son is a future D2/D3 player it's too early for anything to come of it.
Now to answer your question
Be a two way player until a coach says you're no longer a two way. Mine played both ways throughout travel ball and was even recruited as such. When he got to school it was a different story and he became a PO. As for what to specialize in...
Take your son to college games. Go watch a P5 or quality mid major, go watch a bad D1, go watch a bad D3, go watch Juco. Obviously your son is not going to be as good as most of them - he's still going to be undeveloped and unpolished, but is he smooth like the MIFs or is he much much choppier? How is his pop time/arm strength compared to the catchers at the lower levels? This is important because if your son is a plus defender, is smooth and has range just lacks the arm strength or the speed maybe his future is in the field. If he doesn't resemble anything on any of the fields odds are he isn't going to. Maybe his future is behind the plate. Watch the catchers? How much better are they than him?
Go watch and realistically say to yourself is my son talented enough to play here if he has another year and a half of development. Sometimes the answer is no and that's fine. But regardless you can see the level they're playing at and what work needs to be done.
Ps. If he's actually 6 foot, he can easily get 200lbs in that frame.