I'm with Fenway. The earlier you get that testing out of the way, the better.
I'd also add this: if he's not yet well into the physique he'll have at least as a junior, it's tough to project his development.
S attended both the Stanford and Headfirst camp as a rising junior; his testing was done, grades had a track record (a ninth grader will have one year of - probably - basic courses completed), course rigor was readily apparent (again, a ninth grader hasn't the academic track record demonstrating the rigor demanded by the top academic schools), and he had grown to be at least half-pint man size (to the point where his college physique was pretty clear). He caught the eye of some coaches which played to his benefit when he returned the following year.
The differences between a rising 11th grader and a rising 12th grader aren't as extreme as between a rising 10th grader and a rising 12 grader. If you son can hold his own against the rising seniors who attend these camps, then he may catch a coach's eye for the future; if he will be dominated by the older kids, it will not effect his potential recruitablity, but he will not catch a coach's eye and your money may be better spent in things like lessons, local travel, etc.
i would also suggest planning visits to schools so the family can begin the learning process of college selection (e.g., big city, rural, northeast or south, D1 or D3, etc.). While his preferences may evolve over time, might as well get started early.